angle encoders - california institute of technologybicep.caltech.edu/~yuki/servo/208_736-27.pdf ·...

Angle Encoders

Feb

ruary

2004

Angle encoders with integral bearing forseparate shaft coupling

Angle encoders with integral bearingand integrated stator coupling

Angle encoders without integral bearing

Information about• Rotary Encoders• Position Encoders for Servo Drives• Exposed Linear Encoders• Sealed Linear Encoders• HEIDENHAIN Subsequent Electronics• HEIDENHAIN Controlsare available upon request or on theInternet under www.heidenhain.de.

This catalog supersedes all previouseditions, which thereby become invalid.The basis for ordering from HEIDENHAINis always the catalog edition valid whenthe contract is made.

Standards (ISO, EN, etc.) apply only whereexplicitly stated in the catalog.

ContentsOverview

HEIDENHAIN Angle Encoders 4

Selection Guide Angle encoders with integral bearing 6

Angle encoders without integral bearing 8

Technical Characteristics and Mounting Information

Measuring Principles Measuring standard, absolute measuring principle,incremental measuring principle

10

Scanning the Measuring Standard 12

Measuring Accuracy 14

Mechanical Design

Types and Mounting

RON, RPN, RCN 18

ROD 20

ERP, ERA 180, ERM, ERO 22

ERA 700, ERA 800 24

General Mechanical Information 26

Specifications Series or Model Accuracy

Angle Encoders withIntegral Bearing andIntegrated StatorCoupling

RON/RCN 200 series ± 5"/± 2.5" 28

RON 785 ± 2" 30

RON/RCN 700 series ± 2" 32

RON/RPN/RCN 800 series ± 1" 34

RON 905 ± 0.4" 36

Angle Encoders withIntegral Bearing forSeparate Shaft Coupling

ROD 200 series ± 5" 38

ROD 780 ± 2" 40

ROD 880 ± 1" 40

Angle Encoders withoutIntegral Bearing

ERP 880 ± 1" 42

ERA 180 series to ± 3.5" 44

ERM 280 series to ± 11" 48

ERO 785 series to ± 2.5" 50



Electrical Connections

Interfaces and

Pin Layouts

Incremental signals � 1 VPP 58

Incremental signals � TTL 60

EnDat absolute position values 62

Connecting Elements and Cables 67

General Electrical Specifications 70

Evaluation and Display Units

Display Units, Interpolation and Digitizing Electronics Interface Cards,

HEIDENHAIN Measuring Equipment72

4

HEIDENHAIN Angle Encoders

The term angle encoder is typically used todescribe encoders that have an accuracy ofbetter than ± 5" and a line count above10000.

In contrast, rotary encoders are encodersthat typically have an accuracy of more than± 10".

Angle encoders are found in applicationsrequiring precision angular measurement toaccuracies within several arc seconds.

Examples:• Rotary tables on machine tools• Swivel heads on machine tools• C-axes of lathes• Measuring machines for gears• Printing units of printing machines• Spectrometers• Telescopesetc.

The tables on the following pages listdifferent types of angle encoders to suit thevarious applications and meet differentrequirements.

Angle encoders can have one of threedifferent mechanical designs:

Angle encoders with integral bearing,

hollow shaft and integrated stator

coupling

Because of the design and mounting of thestator coupling, it must only absorb thattorque caused by friction in the bearingduring angular acceleration of the shaft. RON,

RPN and RCN angle encoders thereforeprovide excellent dynamic performance.With an integrated stator coupling, thestated system accuracy also includes thedeviations from the shaft coupling.

Other advantages:• Compact size for limited installation space• Hollow shaft diameters up to 60 mm for

leading power cables, etc.• Simple installation

Selection Guide on pages 6/7

The RON 886 angle encoder mounted onto the rotary table of a machine tool

RON 886

Rotary table

RON 886 incremental angle encoder

5

ROD 800 incremental angle encoder with K 16 flat coupling

Angle encoders with integral bearing,

for separate shaft coupling

ROD angle encoders with solid shaft areparticularly suited to applications wherehigher shaft speeds and larger mountingtolerances are required. The shaft couplingsallow axial tolerances of ± 1 mm.


Angle encoders without integral bearing

The ERP, ERO and ERA angle encoderswithout integral bearing (modular angleencoders) are intended for integration inmachine elements or apparatuses. Theyare designed to meet the followingrequirements:• Large hollow shaft diameter (up to 10 m

with a scale tape)• High shaft speeds up to 40000 rpm• No additional starting torque from shaft

seals• Segment angles

The ERM modular magnetic encoder isparticularly suited to applications with loweraccuracy requirements, such as the C axison lathes or auxiliary axes.


ERA 180 incremental angle encoder

Overv

iew

6

Selection Guide

Angle Encoders with Integral Bearing

Series System accuracy and

line count

Recommended measuring step/

absolute positions/rev.

Overall dimensions

in mmMax. mechanically

permissible speed

With integral stator coupling

RON 200

Incremental± 5" with 18000 0.0001° 3000 rpm

5-fold interpolation 0.001°10-fold interpolation 0.0005°

± 5" with 9000 0.005°

± 2.5" with 18000 0.0001°

RCN 200

Absolute± 5"/± 2.5" with 16384 � 0.0001°

26 bits � 67108864 positions/rev.

RON 700


± 2" with 18000± 2" with 36000

0.0001° 1000 rpm

RCN 700

Absolute± 2" with 32768 � 0.0001°

27 bits � 134 217728 positions/rev.

RON 800


RPN 800

Incremental± 1" with 90000(180000 signal periods)

0.00001°

RCN 800

Absolute± 1" with 32768 � 0.0001°

27 bits � 134 217728 positions/rev.

RON 900

Incremental± 0.4" with 36000 0.00001° 100 rpm

For separate shaft coupling

ROD 200

Incremental± 5" with 18000 0.0001°

ROD 260: 0.005°ROD 270: 0.0005°

10000 rpm

ROD 700

Incremental± 2" with 18000± 2" with 36000

0.0001° 1000 rpm

ROD 800

Incremental± 1" with 36000 0.00005°

7

Incremental signals/

data interface

Reference marks Model See

page

� 1 VPP One ordistance-coded

RON 285 28

� TTL x 5/105/10-fold interpolation

One RON 275

� TTL x 2 (1 MHz)2-fold interpolation

One RON 225


RON 287

� 1 VPPEnDat

– RCN 226


RON 785 30


RON 786 32

� 1 VPPEnDat

– RCN 727


RON 886 34

One RPN 886

– RCN 827

� 11 µAPP One RON 905 36


ROD 280 38

� TTL (1 MHz) One ROD 260

� TTL10-fold interpolation

One ROD 270


ROD 780 40


ROD 880 40

RON 285

ROD 285

RON 786

ROD 780

RON 905

8

Selection Guide

Angle Encoders without Integral Bearing

Series Line count/

System accuracy1)

Recommended

measuring step

Overall dimensions

in mmDiameter

D1/D2

Max. mech.

permissible

speed

Grating on solid scale carrier

ERP 880

Glass disk withinterferentialgrating

90000/± 1" 1)

(180000 signalperiods)

0.00001° – 1000 rpm

ERA 180

Steel drumwith axialgrating

6000/± 7.5" to36000/± 2.5" 1)

0.0015° to0.0001°

D1: 40 to 512 mmD2: 80 to 562 mm

40000 rpm to6000 rpm

ERM 200

Steel drumwith magneticgrating

600/± 36" to2600/± 10" 1)

0.003° to 0.001° D1: 40 to 295 mmD2: 75.44 to

326.9 mm

24000 rpm to5000 rpm

as of mid-2004:40000 rpm to7000 rpm

ERO 785

Glass disk withradial grating

36000/± 4.2" to± 2.2" 1)

0.0001° D1: 47 mmD2: 129.9 mm

8000 rpm

D1: 102 mmD2: 182 mm

6000 rpm

D1: 155.1 mmD2: 256.9 mm

4000 rpm

Grating on steel tape

ERA 700

For insidediametermounting

Full circle1)

36000/± 3.5"45000/± 3.4"90000/± 3.2"

0.0001° to0.00002°

458.62 mm573.20 mm

1146.10 mm

500 rpm

Segment2)

50001000020000

318.58 mm458.62 mm573.20 mm

ERA 800

For outsidediametermounting

Full circle1)

36000/± 3.5"45000/± 3.4"

0.0001° to0.00005°

458.04 mm572.63 mm

100 rpm

Segment2)

50001000020000

317.99 mm458.04 mm572.63 mm

1) Without installation. Additional error caused by mounting inaccuracy and inaccuracy from the bearing of the measured shaft are not included.2) Angular segment from 50° to 200°; see Measuring Accuracy for the accuracy.

��

9

ERO 785

ERM 280

ERA 880

Output signals Reference marks Model See

page

� 1 VPP One ERP 880 42

� 1 VPP One ERA 180 44

� 1 VPP One ERM 280 48

� 1 VPP One ERO 785 50

� 1 VPP Distance-coded(nominal incrementof 1000 gratingperiods)

ERA 780C full circle 52

ERA 781C segment

� 1 VPP Distance-coded(nominal incrementof 1000 gratingperiods)

ERA 880C full circle 54

ERA 881C segmentwith tensioning elements

ERA 882C segment with-out tensioning elements

ERA 180

ERP 880

10

Measuring Principles

Measuring Standard

HEIDENHAIN encoders incorporatemeasuring standards of periodic structuresknown as graduations. These graduationsare applied to a glass or steel substrate.Glass scales are used primarily in encodersfor speeds up to 10000 rpm. For higherspeeds—up to 40000 rpm—steel drumsare used. The scale substrate for largediameters is a steel tape.

These precision graduations are manu-factured in various photolithographicprocesses. Graduations are fabricated from:• extremely hard chromium lines on glass

or gold-plated steel drums,• matte-etched lines on gold-plated steel

tape, or• three-dimensional structures etched into

quartz glass.

These photolithographic manufacturingprocesses—DIADUR and AURODUR—developed by HEIDENHAIN producegrating periods of:• 40 µm with AURODUR,• 10 µm with DIADUR, and• 4 µm with etched quartz glass

These processes permit very fine gratingperiods and are characterized by a highdefinition and homogeneity of the lineedges. Together with the photoelectricscanning method, this high edge definitionis a precondition for the high quality of theoutput signals.

The master graduations are manufacturedby HEIDENHAIN on custom-built high-precision ruling machines.

Magnetic encoders use a graduation carrierof magnetizable steel alloy. A graduationconsisting of north poles and south poles isformed with a grating period of 400 µm(MAGNODUR process). Due to the shortdistance of effect of electromagneticinteraction, and the very narrow scanninggaps required, finer magnetic graduationsare not practical.

Absolute encoders feature multiple codedgraduation tracks. The code arrangementprovides the absolute position information,which is available immediately afterrestarting the machine. The track with thefinest grating structure is interpolated forthe position value and at the same time isused to generate an incremental signal (seeEnDat Interface).

Circular graduations of absolute angle encoders

Absolute Measuring Method

Schematic representation of a circular scale with absolute grating

11

Incremental Measuring Method

With incremental measuring methods,

the graduation consists of a periodic gratingstructure. The position information isobtained by counting the individualincrements (measuring steps) from somepoint of origin. Since an absolute referenceis required to ascertain positions, the scalesor scale tapes are provided with an additionaltrack that bears a reference mark. Theabsolute position on the scale, establishedby the reference mark, is gated withexactly one measuring step.The reference mark must therefore bescanned to establish an absolute referenceor to find the last selected datum.

In some cases, however, this may requirea rotation up to nearly 360°. To speed andsimplify such “reference runs,” manyencoders feature distance-coded refe-

rence marks—multiple reference marksthat are individually spaced according to amathematical algorithm. The subsequentelectronics find the absolute reference aftertraversing two successive referencemarks—meaning only a few degreestraverse (see table).

Encoders with distance-coded referencemarks are identified with a “C” behind themodel designation (e.g. RON 786C).

With distance-coded reference marks, theabsolute reference is calculated bycounting the signal periods between tworeference marks and using the followingformula:

Circular graduations of incremental angle encoders

�1 = (abs A–sgn A–1) x I + (sgn A–sgn D) x abs MRR

where:

A = 2 x abs MRR–IGP

and:�1 = Absolute angular position of the first

traversed reference mark to thezero position in degrees

abs = Absolute value

sgn = Sign function (“+1” or ”–1”)

MRR = Measured distance between thetraversed reference marks in degrees

I = Nominal increment between twofixed reference marks (see table)

GP = Grating period (line count)

D = Direction of rotation (+1 or –1)Rotation to the right (as seen fromthe shaft side of the angleencoder—see Mating Dimensions)gives “+1”

360°

Line count z Number of

reference marks

Nominal increment I

90000450003600018000

180907236

4°8°

10°20°

22

Distance-coded reference marks on a circular scale

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Info

12

Scanning the Measuring Standard

Photoelectric Scanning

Most HEIDENHAIN encoders operate usingthe principle of photoelectric scanning. Thephotoelectric scanning of a measuringstandard is contact-free, and thereforewithout wear. This method detects evenvery fine lines, no more than a few micronswide, and generates output signals withvery small signal periods.

The finer the grating period of a measuringstandard is, the greater the effect ofdiffraction on photoelectric scanning.HEIDENHAIN uses two scanning principleswith angle encoders:

• The imaging scanning principle

for grating periods from 10 µm toapprox. 40 µm.

• The interferential scanning principle

for very fine graduations with gratingperiods of 4 µm.

Imaging scanning principle

Put simply, the imaging scanning principlefunctions by means of projected-light signalgeneration: two graduations with equalgrating periods are moved relative to eachother—the scale and the scanning reticle.The carrier material of the scanning reticleis transparent, whereas the graduation onthe measuring standard may be applied toa transparent or reflective surface. Whenparallel light passes through a grating, lightand dark surfaces are projected at a certaindistance. An index grating with the samegrating period is located here. When thetwo gratings move relative to each other,the incident light is modulated. If the gapsin the gratings are aligned, light passesthrough. If the lines of one grating coincidewith the gaps of the other, no light passesthrough. Photocells convert thesevariations in light intensity into nearlysinusoidal electrical signals. The speciallystructured grating of the scanning reticlefilters the light current to generate nearlysinusoidal output signals.

The smaller the period of the gratingstructure is, the closer and more tightlytoleranced the gap must be between thescanning reticle and circular scale. Practical

LED light source

Measuring standard

Photocells

Condenser lens

Scanning reticle

Imaging scanning principle

mounting tolerances for encoders with theimaging scanning principle are achievedwith grating periods of 10 µm and larger.

The ROD, RON, RCN, ERA and ERO angleencoders operate according to the imagingscanning principle.

Interferential scanning principle

The interferential scanning principle exploitsthe diffraction and interference of light on afine graduation to produce signals used tomeasure displacement. A step grating isused as the measuring standard: reflectivelines 0.2 µm high are applied to a flat,reflective surface. In front of that is thescanning reticle—a transparent phasegrating with the same grating period as thescale.

When a light wave passes through thescanning reticle, it is diffracted into threepartial waves of the orders –1, 0, and 1,with approximately equal luminous intensity.The waves are diffracted by the scale suchthat most of the luminous intensity is foundin the reflected diffraction orders 1 and –1.These partial waves meet again at thephase grating of the scanning reticle wherethey are diffracted again and interfere. This

Interferential scanning principle (optics schematics)C Grating period� Phase shift of the light wave when passing through the

scanning reticle� Phase shift of the light wave due to motion x of the scale

LED

light source

Photocells

Condenser lens

Scanning reticle

Measuring standard

I90° and I270°photocellsnot shown

13

Magnetic Scanning

produces essentially three waves that leavethe scanning reticle at different angles.Photocells convert this alternating lightintensity into electrical signals.

A relative motion of the scanning reticle tothe scale causes the diffracted wave frontsto undergo a phase shift: when the gratingmoves by one period, the wave front of thefirst order is displaced by one wavelengthin the positive direction, and the wavelengthof diffraction order –1 is displaced by onewavelength in the negative direction. Sincethe two waves interfere with each otherwhen exiting the grating, the waves areshifted relative to each other by two wave-lengths. This results in two signal periodsfrom the relative motion of just one gratingperiod.

Interferential encoders function withaverage grating periods of 4 µm and finer.Their scanning signals are largely free ofharmonics and can be highly interpolated.These encoders are therefore especiallysuited for high resolution and high accuracy.Even so, their generous mountingtolerances permit installation in a widerange of applications.

The RPN 886 and ERP 880 angle encodersoperate according to the interferentialscanning principle.

The magnetic scanning principle uses ameasuring standard of hard magnetic metalcarrying a permanently magneticMAGNODUR graduation. The graduation isformed from alternating north and southpoles. The scale is scanned with magneto-resistive sensors, whose resistance changesin response to a magnetic field. When avoltage is applied to the sensor, the flowingcurrent is modulated according to themagnetic field.

The special geometric arrangement of theresistive sensors ensures a high signalquality, which is a precondition for thesmallest possible deviation within one signalperiod. A single magnetized pole pair on aseparate track produces a reference marksignal. This makes it possible to assign thisabsolute position value to exactly onemeasuring step.

HEIDENHAIN encoders with magneticscanning typically have grating periods of400 µm. Due to the sensitivity of magneticscanning to variations in the scanning gap,smaller grating periods are very difficult toproduce. Therefore, depending on thegraduation circumference, magneticencoders have at most 2600 signal periodsper revolution, and according to theHEIDENHAIN definition are not angleencoders.

Magnetoresistive scanning is used primarilyfor comparatively low-accuracy applications.

The ERM encoders operate according tothe magnetic scanning principle.

Measuring standard

Scanning

reticle

Magnetoresistive scanning principle

Magnetoresistive sensors for B+ and B– not shown

14

Measuring Accuracy

Position deviation

within one

signal period

Position deviation within one signal period

Position

Signal period360 °elec.

Position deviations within one revolution

Po

sit

ion

devia

tio

n

Po

sit

ion

devia

tio

nS

ign

alle

vels

error of the coupling must be added (seeMechanical Design Types and Mounting— ROD).

• For angle encoders without integralbearing, additional deviations resultingfrom mounting, errors in the bearing ofthe drive shaft, and adjustment of thescanning head must be expected (seeMeasuring Accuracy — Angle Encoderswithout Integral Bearing). Thesedeviations are not reflected in the systemaccuracy.

The system accuracy reflects positiondeviations within one revolution as well asthose within one signal period.

Position deviations within one revolution

become apparent in larger angular motions.

Position deviations within one signal

period already become apparent in verysmall angular motions and in repeatedmeasurements. They especially lead tospeed ripples in the speed control loop.These deviations within a signal period arecaused by the quality of the sinusoidal

scanning signals and their subdivision. Thefollowing factors influence the result:• The size of the signal period,• The homogeneity and edge definition of

the graduation,• The quality of the optical filter structures

on the scanning reticle,• The characteristics of the photoelectric

detectors, and• The stability and dynamics during the

further processing of the analog signals.

HEIDENHAIN angle encoders take thesefactors of influence into account, and permitinterpolation of the sinusoidal output signalwith subdivision accuracies of better than± 1% of the signal period (RPN: ± 1.5%).The reproducibility is even better, meaningthat useful electric subdivision factors andsmall signal periods permit small enoughmeasuring steps (see Specifications).

Example:

Angle encoder with 36000 sinusoidal signalperiods per revolutionOne signal period corresponds to 0.01° or 36".At a signal quality of ± 1%, this results inmaximum position deviations within onesignal period of approx. ± 0.0001° or ± 0.36".

The accuracy of angular measurement ismainly determined by:1. The quality of the graduation2. The quality of scanning3. The quality of the signal processing

electronics4. The eccentricity of the graduation to the

bearing,5. The radial deviation of the bearing,6. The elasticity of the encoder shaft and

its coupling with the drive shaft7. The elasticity of the stator coupling

(RON, RPN, RCN) or shaft coupling(ROD)

In positioning tasks, the accuracy of theangular measurement determines theaccuracy of the positioning of a rotary axis.The system accuracy given in theSpecifications is defined as follows:The extreme values of the total deviationsof a position are—referenced to their meanvalue—within the system accuracy ± a.• For angle encoders with integral bearing

and integrated stator coupling, this valuealso includes the deviation due to theshaft coupling.

• For angle encoders with integral bearingand separate shaft coupling, the angle

15

For its angle encoders with integralbearings, HEIDENHAIN prepares individualcalibration charts and ships them with theencoder.

The calibration chart documents theencoder’s accuracy and serves as atraceability record to a calibration standard.For the RON, RPN and RCN, which featurean integrated coupling, the accuracyspecifications already include the error ofthe coupling. For angle encoders withseparate shaft coupling, however, the errorcaused by the coupling is not included inthe encoder specification and must beadded to calculate the total error (seeKinematic error of transfer under MechanicalDesign Types and Mounting – ROD).

Angle Encoders with Integral Bearing

The manufacturer’s inspection certificate

certifies the accuracy of the encoder. Thecalibration standard is indicated in orderto certify the traceability to the nationalstandard.

The reversal error depends on the shaftcoupling:For angle encoders with integrated statorcoupling the values are:• RON, RCN 200 0.8"• RON, RPN, RCN 700/800 0.6"

The accuracy of angle encoders isascertained through five forward and fivebackward measurements. The measuringpositions per revolution are chosen todetermine very exactly not only the long-range error, but also the position errorwithin one signal period.

All measured values determined in thismanner lie within or on the graphicallydepicted envelope curve. The mean value

curve shows the arithmetic mean of themeasured values, whereby the reversalerror is not included.

Guaranteed accuracy grade of the measured object

Calibration chart example: RON 285

1 Graphic representation of error• Envelope curve• Mean value curve

2 Results of calibration

1

2

16

Measuring Accuracy

Angle Encoders without Integral Bearing

In addition to the system accuracy, themounting and adjustment of the scanninghead normally have a significant effect onthe accuracy that can be achieved withangle encoders without integral bearings.Of special importance are the mountingeccentricity and radial runout of the driveshaft.

To evaluate the accuracy of angle

encoders without integral bearing (ERA,ERM and ERO), each of the significanterrors must be considered individually.

1. Directional deviations of the graduation

ERA 180, ERM and ERO: The extremevalues of the directional deviation withrespect to their mean value are shown inthe Specifications as the graduationaccuracy for each model. The graduationaccuracy and the position deviation withina signal period comprise the systemaccuracy.

ERA 700 and ERA 800 series

The extreme values of the directionaldeviations depend on• the graduation accuracy,• the irregular scale-tape expansion during

mounting, and• deviations in the scale-tape butt joints

(only for ERA 780C/ERA 880C).The special graduation manufacturingprocess and the butt joints preciselymachined by HEIDENHAIN reducedirectional deviations of the graduationto within 3 to 5 angular seconds (withaccurate mounting).

2. Error due to eccentricity of the

graduation to the bearing

Under normal circumstances the bearingwill have a certain amount of radial runoutor shape deformation after the disk/hubassembly (ERO), circumferential-scale drum(ERA 180, ERM), or scale tape (ERA 78xCand ERA 88xC) is mounted. When centeringusing the centering collar of the hub or thedrum, please note that HEIDENHAINguarantees an eccentricity of the graduationto the centering collar of under 1 µm. Forthe modular angle encoders, this accuracyvalue presupposes a diameter deviation ofzero between the encoder shaft and the“master shaft.” If the centering collar iscentered on the bearing, then in aworst-case situation both eccentricityvectors could be added together.

The following relationship exists betweenthe eccentricity e, the mean graduationdiameter D and the measuring error ��

(see illustration below):

��= ± 412 ·eD

��= Measuring error in seconds of arce = Eccentricity of the radial grating to the

bearing in µmD = Mean graduation diameter (ERO) or

drum outside diameter (ERA 180,ERM) and scale tape mount diameter(ERA 78xC/ERA 88xC) in millimeters

M = Center of graduation� = “True” angle�‘ = Scanned angle

ERA 781C, ERA 881C, ERA 882C

In these segment solutions, the additionalangular error �� occurs when the nominalscale-tape bearing-surface diameter is notexactly maintained:

��= (1 – D’/D) · � · 3600

where��= Segment deviation in angular seconds� = Segment angle in degreesD = Nominal scale-tape carrier diameterD’ = Actual scale-tape carrier diameter

This error can be eliminated if the line countper 360° valid for the actual scale-tapecarrier diameter D’ can be entered in thecontrol. The following relationship is valid:

z’ = z · D’/D

where z = Nominal line count per 360°z’ = Actual line count per 360°

The angle actually traversed in individualsegment solutions should be measuredwith a comparative encoder, such as anangle encoder with integral bearing.

�

��

�

��

Angular error due to variations in scale-tape carrier diameter Eccentricity of the graduation to the bearing

Scanning unit

Segment

Segment version

Center of graduation

17

4. Position error within one signal period

��u

The scanning units of all HEIDENHAINencoders are adjusted so that the maximumposition error values within one signalperiod will not exceed the values listedbelow, with no further electrical adjustingrequired at mounting.

Model Meangraduationdiameter D

Deviationper 1 µm ofeccentricity

ERP 880 D = 126 mm ± 3.3"

ERA 180 D = 80 mmD = 130 mmD = 180 mmD = 250 mmD = 330 mmD = 485 mmD = 562 mm

± 5.2"± 3.2"± 2.3"± 1.6"± 1.2"± 0.8"± 0.7"

ERM 280 D = 75 mmD = 113 mmD = 130 mmD = 150 mmD = 176 mmD = 260 mmD = 325 mm

± 5.5"± 3.6"± 3.2"± 2.7"± 2.3"± 1.6"± 1.3"

ERO 785 D = 110 mmD = 165 mmD = 240 mm

± 3.7"± 2.5"± 1.7"

ERA 78xC D = 320 mmD = 460 mmD = 570 mmD = 1145 mm

± 1.3"± 0.9"± 0.7"± 0.4"

ERA 88xC D = 320 mmD = 460 mmD = 570 mm

± 1.3"± 0.9"± 0.7"

3. Error due to radial deviation of the

bearing

The equation for the measuring error �� isalso valid for radial deviation of the bearingif the value of e is replaced with theeccentricity value, i.e. half of the radialdeviation (half of the displayed value).

Bearing compliance to radial shaft loadingcauses similar errors.

Resultant measured deviations �� for various eccentricity values eas a function of mean graduation diameter D

Mean graduation diameter D [mm]

Measu

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[seco

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Model Line count Position errorwithin one signalperiod ��u

ERP 880 90000 � ± 0.15"

ERA 180 360001800090006000

� ± 0.5"� ± 1"� ± 2"� ± 2.5"

ERM 280 26002048140012001024

900600

� ± 6"� ± 7"� ± 11"� ± 12"� ± 13"� ± 15"� ± 22"

ERO 785 36000 � ± 0.5"

ERA 78xC,

ERA 88xC

900004500036000

� ± 0.2"� ± 0.4"� ± 0.5"

The values for the position errors withinone signal period are already included in thesystem accuracy. Larger errors can occur ifthe mounting tolerances are exceeded.

18

Mechanical Design Types and Mounting

RON, RPN, RCN

RON, RPN and RCN angle encoders havean integral bearing, hollow shaft andintegrated stator coupling. The measuredshaft is directly connected with the shaft ofthe angle encoder. The reference mark canbe assigned to a desired angular position ofthe measured shaft from the rear of theencoder during mounting.

The graduated disk is rigidly affixed to thehollow shaft. The scanning unit rides on theshaft on ball bearings and is connected tothe housing with a coupling on the statorside. During angular acceleration of the shaft,the coupling must absorb only that torquecaused by friction in the bearing. Angleencoders with integrated stator couplingtherefore provide excellent dynamicperformance.

Mounting

The housing of the RON, RPN and RCN isfirmly connected to the stationary machinepart with an integral mounting flange and acentering collar. Liquids can easily flowaway through drainage channels on theflange.

Shaft coupling with ring nut

The RON, RPN and RCN series have ahollow through shaft. For installation, thehollow through shaft of the angle encoderis placed over the machine shaft, and isfixed with a ring nut from the front of theencoder.

RON 905 shaft coupling

The RON 905 has a bottomed hollow shaft.The shaft connection is made via an axialcentral screw.

Front-end shaft coupling

It is often advantageous, especially withrotary tables, to integrate the angle encoderin the table so that it is freely accessiblewhen the rotor is lifted. This installation fromabove reduces mounting times, increasesthe ease for servicing, and improves theaccuracy, since the encoder is locatednearer to the rotary table bearing and themeasuring or machining plane. The hollowshaft is attached with the threaded holeson the face, using special mountingelements fitted to the individual design (notincluded in delivery).

To comply with radial and axial runoutspecifications, the internal hole � and theshoulder surface � are to be used asmounting surfaces for shaft coupling at theface of the encoder.

Front-end shaft coupling with RON 786

Customized version

Rotor

RON 786

Stator

Mounting an RON angle encoder with hollow through shaft

Centering collar

Ring nut

Drive shaft

Cross section of the RON 886 angle encoder

Light source(LED) withcondenser lens Photocells

Hollow shaft

Integrated coupling

DIADUR

graduated disk

19

Ring nut for RON/RCN 200

Id. Nr. 336669-03

Ring nut for RON 785

Id. Nr. 336669-05

Ring nut for RON 786

RON/RPN 886

RCN 727/RCN 827

Id. Nr. 336669-01

Ring nuts for RON, RPN and RCN

HEIDENHAIN offers special ring nuts forthe RON, RPN and RCN angle encoderswith integral bearing and hollow throughshaft with integrated coupling. Choose thetolerance of the shaft thread such that thering nut can be tightened easily, with aminor axial play. This guarantees that theload is evenly distributed on the shaftconnection, and prevents distortion of thehollow shaft of the angle encoder.

L1 L2 D1 Threaddiameter D2

D3

RON 785 62±0.2 55 ( 49.052±0.075)

49.469±0.059

( 50.06)

RON 786

RON/RPN 886

RCN 727/RCN 827

70±0.2 65 ( 59.052±0.075)

59.469±0.059

( 60.06)

*) Thread diameter

20

Angle encoders of the ROD product familyrequire a separate coupling for connectionto the drive shaft. The shaft coupling com-pensates axial movement and misalignmentbetween the shafts, preventing excessiveload on the encoder bearing of the angleencoder. It is important that the encodershaft and the drive shaft be optimally alignedfor high measurement accuracies to berealized. The HEIDENHAIN product programincludes diaphragm couplings and flatcouplings designed for connecting the shaftof the ROD angle encoder to the drive shaft.

Mounting

ROD angle encoders are provided with anintegral mounting flange with centeringcollar. The encoder shaft is connected tothe drive shaft by way of a diaphragmcoupling or flat coupling.

Shaft couplings

The shaft coupling compensates axialmovement and misalignment between theencoder shaft and the drive shaft, preventingexcessive load on the encoder bearing ofthe angle encoder.

Radial misalignment �

Angular error �

Axial motion �

Mountingexample

ROD 880

Rotarytable

ROD 880

Additionalprotectionagainst fluids

Shaftcoupling

Mountingan ROD

ROD

Centering collar

Flat coupling


ROD

ROD 200 Series ROD 700 Series, ROD 800 Series

Shaft coupling K 03

Diaphragm couplingK 18

Flat couplingK 01

Diaphragm couplingK 15

Flat couplingK 16

Flat coupling

Hub bore 10 mm 14 mm

Kinematic transfer error ± 2" ± 3" ± 1" ± 0.5"at � � 0.05 mm and � � 0.03°at � � 0.1 mm and � � 0.09°

Torsional rigidity 1500 Nm/rad 1200 Nm/rad 4000 Nm/rad 6000 Nm/rad 4000 Nm/rad

Permissible torque 0.2 Nm 0.5 Nm

Permissible radial offset � � 0.3 mm

Permissible angular error� � 0.5° � 0.2° � 0.5°

Permissible axial offset � � 0.2 mm � 0.1 mm � 1 mm

Moment of inertia (approx.) 20 · 10–6 kgm2 75 · 10–6 kgm2 200 · 10–6 kgm2 400 ·10–6 kgm2

Permissible speed 10000 rpm 1000 rpm 3000 rpm 1000 rpm

Torque for locking screws

(approx.)

1.2 Nm 2.5 Nm 1.2 Nm

Weight 100 g (0.22 lb) 117 g (0.258 lb) 180 g (0.4 lb) 250 g (0.55 lb) 410 g (0.9 lb)

21

K 03 diaphragm coupling

Id. Nr. 200313-04

K 18 flat coupling

Id. Nr. 202227-01

K 01 diaphragm coupling

Id. Nr. 200301-02

K 16 flat coupling

Id. Nr. 258878-01

K 15 flat coupling

Id. Nr. 255797-01

Dimensions in mm

22


ERP

The ERP 880 modular angle encoderconsists of the following components:scanning unit, disk/hub assembly, and PCB.Cover caps for protection from contact orcontamination can be supplied asaccessories.

Mounting — ERP

First the scanning unit is mounted on thestationary machine part with an alignmentof ± 1.5 µm to the shaft. Then the frontside of the disk/hub assembly is screwedonto the shaft, and is also aligned with amaximum eccentricity of ± 1.5 µm to thescanning unit. Then the PCB is attachedand connected to the scanning unit. Fineadjustment takes place by “electricalcentering” using the PWM 9 (seeHEIDENHAIN Measuring Equipment) andan oscilloscope. The ERP 880 can beprotected from contamination by coveringit with a cap.

Mounting theERP 880

(in principle)

IP 40 cover cap

With sealing ring for IP 40 protectionCable 1 m with male coupling, 12-pinId. Nr. 369774-01

IP 64 cover cap

With shaft seal for IP 64 protectionCable 1 m with male coupling, 12-pinId. Nr. 369774-02

23

ERA 180, ERM, ERO

The ERA 180, ERM and ERO modularangle encoders consist of either acircumferential-scale drum (ERA, ERM)or a disk/hub assembly (ERO) and thecorresponding scanning unit. Special designfeatures of the modular angular encodersassure comparably fast mounting and easyadjustment.

Mounting — ERA 180, ERM

The circumferential-scale drum is slid ontothe drive shaft and fastened with screws.HEIDENHAIN recommends using atransition fit for mounting the scale drum.For mounting, the scale drum may be slowlywarmed on a heating plate over a period ofapprox. 10 minutes to a temperature ofmax. 100 °C. The scale drum is centered viathe centering collar on its inner circum-ference. The scanning unit is mounted withthe spacer foil attached to the circumferential-scale drum. The scanning unit is pressedagainst the foil, the screws are tightened,and the foil is removed.

To protect the ERA 180 from contamination,HEIDENHAIN supplies a protective coverfor drum diameters up to 180 mm. Forlarger diameters, HEIDENHAIN recommendsintegrating a protective cover into themachine itself.

Mounting — ERO

The disk/hub assembly is slid onto the driveshaft, centered, and fastened with screws.The scanning unit is then slid onto thecentering collar of the hub and the screwsare tightened. The gap between thegraduated disk and the scanning unit is setwith spacer foils.

Crosssection ofERO 785

Hub

Graduated disk

Scanning unit

Crosssection ofERA 180

Scanning unit

Scale drum

Protective cover

Mounting theERA 180 andthe ERM 280

(in principle)

24


ERA 700 and ERA 800 Series

The encoders of the ERA 700 and ERA 800series consist of a scanning unit and a one-piece steel scale tape up to 30 m in length.The tape is mounted on the• inside diameter (ERA 700 series) or• outside diameter (ERA 800 series)of a machine element.

The ERA 780C and ERA 880C angleencoders are designed for full-circle

applications. Thus, they are particularlysuited to hollow shafts with large insidediameters (from approx. 300 mm) and toapplications requiring an accuratemeasurement over a large circumference,e.g. large rotary tables, telescopes, etc.

In applications where there is no full circle,or measurement is not required over 360°,segment angles are available fordiameters from 300 mm.

Mounting the scale tape for full-circle

applications

ERA 780C: An internal slot with a certaindiameter is required as scale tape carrier.The tape is inserted starting at the butt jointand is clicked into the slot. The length is cutso that the tape is held in place by its ownspring force. To make sure that the scaletape does not move within the slot, it isfixed with adhesive at multiple points in thearea of the butt joint.

ERA 880C: The scale tape is supplied withthe halves of the tensioning cleat alreadymounted on the tape ends. An external

slot is necessary for mounting. Space mustalso be provided for the tensioning cleat.The tape is placed in the outside slot of themachine (along slot edge) and is tensionedusing the tensioning cleat. The scale tapeends are manufactured so exactly that onlyminor signal-form deviations can occur in thearea of the butt joint.

Mounting the scale tape for segment

angles

ERA 781C: An internal slot with a certaindiameter is required. Both bearing piecesare fixed in this slot, and are adjusted withcam disks so that the scale can be pressedinto the slot while under tension.

Spring

ERA 881C: The scale tape is supplied withpremounted bearing pieces. An externalslot with recesses for the bearing pieces isrequired for placing the scale tape. Thescale tape is fitted with tension springs,which create an optimal bearing preload forincreasing the accuracy of the scale tape,and evenly distribute the expansion overthe entire length of the scale tape.

ERA 882C: An external slot or one-sidedaxial stop is recommended for placing thescale tape. The scale tape is suppliedwithout tensioning elements. It must bepreloaded with a spring balance, and fixedwith the two oblong holes.

Cam disks

25

��

�

The following must be kept in mind forsegment applications:• Determining the slot diameter

In order to guarantee the correct func-tioning of the distance-coded referencemarks, the circumference of the theoreticalfull circle must be a multiple of 1000 gratingperiods. This also facilitates adaptation tothe NC control, which mostly can onlycalculate integer line counts. The connec-tion between the basic slot diameter andthe line count can be seen in the table.

• Segment angles

The measuring range available for thesegment angle should be a multiple of1000 signal periods, since these versionsare available more quickly.

Mounting the scanning head

A spacer foil is placed against the scaletape. The scanning head is pushed upagainst the spacer foil in such a way thatthe foil is only located between the twomechanical support points on the mountingbracket. The scanning head is secured inthis position and the foil is removed.

Adjusting the scanning head

Accurate alignment of the scanning headwith the scale tape is critical for theERA 700/800 to provide accurate andreliable measurements (Moiré setting). Ifthe scanning head is not properly aligned,the quality of the output signals will bepoor.

The quality of the output signals can bechecked using HEIDENHAIN’s PWT phase-

angle testing unit. When the scanninghead is moved along the scale tape, thePWT unit graphically displays the quality ofthe signals as well as the position of thereference mark. The PWM 9 phase angle

measuring unit calculates a quantitativevalue for the deviation of the actual outputsignals from the ideal signal (seeHEIDENHAIN Measuring Equipment).

Basic slot diameter Line count projected onto a

full circle

ERA 781C 318.58 + n · 12.73111 25000 + n · 1000

ERA 881C/

ERA 882C

317.99 + n · 12.73178 25000 + n · 1000

Measuring range

Theoretical full circle

Basic slot diameter

PWT

Spacer foil

26

Protection

Unless otherwise indicated, all RON, RPN,RCN and ROD angle encoders meet protec-tion standard IP 67 according to IEC 60529.This includes housings and cable outlets.The shaft inlet provides protection to IP 64.

Splash water should not contain anysubstances that would have harmful effectson the encoder parts. If protection to IP 64of the shaft inlet is not sufficient (such aswhen the angle encoder is mountedvertically), additional labyrinth seals shouldbe provided.

RON, RPN, RCN and ROD angle encodersare equipped with a compressed air inlet.Connection to a source of compressed airslightly above atmospheric pressureprovides additional protection againstcontamination.

General Mechanical Information

Temperature range

The operating temperature range

indicates the limits of ambient temperaturewithin which the values given in the specifi-cations for angle encoders are maintained(DIN 32878).

The storage temperature range of –30 to+80 °C (–22 to +176 °F) is valid when theunit remains in its packaging. The RON 905should not be stored at temperatures beyond–30 to +50 °C (–22 to +122 °F): exceedingthis temperature range could result inirreversible changes of up to 0.05 angularseconds to the unit’s accuracy.

For this purpose, HEIDENHAIN offers theDA 300 compressed air unit (filtercombination with pressure regulator andfittings). The compressed air introducedinto the encoder must fulfill the requirementsof the following quality classes as perISO 8573-1:• Max. particle size and density of solid

contaminants:Class 4 (max. particle size: 15 µm,max. particle density: 8 mg/m3)

• Total oil content:Class 4 (oil content: 5 mg/m3)

• Max. pressure dew point:Class 4 (+29 °C at 10 · 105 Pa)no classification

The following components are necessaryfor connection to the RON, RPN, RCN andROD angle encoders:

M5 connecting piece for

RON/RPN/RCN/ROD

with gasket and throttle (dia. 0.3 mm)for air-flow rate from 1 to 4 l/minId. Nr. 207835-04

M5 coupling joint, swiveling

with gasketId. Nr. 207834-02

For more information, ask for our DA 300product information sheet.

DA 300

27

Protection against contact

After encoder installation, all rotating parts(coupling on ROD, locking ring on RON,RPN and RCN) must be protected againstaccidental contact during operation.

Acceleration

Angle encoders are subject to various typesof acceleration during operation andmounting.• The permissible angular acceleration

for all RON, RPN, RCN and ROD angleencoders is over 105 rad/s2.

• The indicated maximum values forvibration are valid according toIEC 60068-2-6.

• The maximum permissible accelerationvalues (semi-sinusoidal shock) for shock

and impact are valid for 6 ms(IEC 60068-2-27).Under no circumstances should ahammer or similar implement be used toadjust or position the encoder.

Natural frequency fN of coupling

The rotor and shaft coupling of ROD angleencoders, as well as the stator and statorcoupling of RON, RPN and RCN angleencoders, form a single vibrating spring-mass system.

The natural frequency fN should be ashigh as possible. With the RON, RPN andRCN angle encoders, the natural frequencyfN is given in the respective specifications.A prerequisite for the highest possiblenatural frequency of ROD angle encoders

is the use of a shaft coupling with a hightorsional rigidity C.

fN = ·

fN: Natural frequency in HzC: Torsional rigidity of the coupling in Nm/rad�: Moment of inertia of the rotor in kgm2

If radial and/or axial acceleration occursduring operation, the effect of the rigidity ofthe encoder bearing, the encoder statorand the coupling are also significant. If suchloads occur in your application, HEIDENHAINrecommends consulting with the mainfacility in Traunreut.

12 ·

CI

Expendable parts

HEIDENHAIN encoders contain componentsthat are subject to wear, depending on theapplication and manipulation. These includein particular the following parts:• LED light source• Cables with frequent flexingAdditionally for encoders with integralbearing:• Bearings• Shaft sealing rings for rotary and angular

encoders• Sealing lips for sealed linear encoders

System tests

Encoders from HEIDENHAIN are usuallyintegrated as components in larger systems.Such applications require comprehensive

tests of the entire system regardless ofthe specifications of the encoder.The specifications given in the brochureapply to the specific encoder, not to thecomplete system. Any operation of theencoder outside of the specified range orfor any other than the intended applicationsis at the user’s own risk.In safety-oriented systems, the higher-level system must verify the positionvalue of the encoder after switch-on.

DIADUR, AURODUR and MAGNODURare registered trademarks ofDR. JOHANNES HEIDENHAIN GmbH,Traunreut.

Mounting

Work steps to be performed and dimen-sions to be maintained during mountingare specified solely in the mountinginstructions supplied with the unit. All datain this catalog regarding mounting aretherefore provisional and not binding; theydo not become terms of a contract.

28

RON/RCN 200 Series

• Integrated stator coupling

• Hollow through shaft, diameter 20 mm

• System accuracy ± 5" and ± 2.5"

� = Bearing� = Required mating dimensions

Dimensions in mm

Accuracy ± 2.5" ± 5"

D1 20H6 � 20H7 �

D2 30H6 � 30H7 �

D3 20g6 � 20g7 �

T 0.01 0.02

29

Incremental Absolute

RON 225 RON 275 RON 275 RON 285 RON 287 RCN 226 RCN 226

Incremental signals � TTL x 2 � TTL x 5 � TTL x 10 � 1 VPP � 1 VPP

Line countIntegr. interpolation*

Output signals/rev

90002-fold/18000

180005-fold/90000

1800010-fold/180000

18000 16384

Reference mark* One RON 2xx: OneRON 2xxC: Distance-coded

–

Output frequencyCutoff frequency –3dB

Max. 1 MHz–

Max. 250 kHz–

Max. 1 MHz–

–� 180 kHz � 180 kHz

Absolute position values – EnDat

Positions per rev. – 67108864 (26 bits)� 0.0000054° � 0.02"

Elec. perm. speed – 1500 rpm

Recommended

measuring step

0.005° 0.001° 0.0005° 0.0001° 0.0001°

System accuracy ± 5" ± 2.5" ± 5" ± 2.5"

Power supply 5 V ± 10%/max. 150 mA (without load) 5 V ± 5%/max. 350 mA(without load)

Electrical connection* Cable 1 m, radial, also usable axially;with or without coupling

Cable 1 m, radial,also usable axially;with or without coupling

Max. cable length 50 m 150 m 150 m

Mech. permissible speed Max. 3000 rpm Max. 3000 rpm

Starting torque � 0.08 Nm at 20 °C (68 °F) � 0.08 Nm at 20 °C (68 °F)

Moment of inertia of rotor 73 · 10–6 kgm2 73 · 10–6 kgm2

Natural frequency � 1200 Hz � 1200 Hz

Permissible axis motion

of measured shaft

± 0.1 mm ± 0.1 mm

Vibration 55 to 2000 HzShock 6 ms

� 100 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

� 100 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

Max. operating

temperature

70 °C (158 °F) 50 °C (122 °F) 70 °C (158 °F) 50 °C (122 °F)

Min. operating

temperature

Moving cableRigid cable

–10 °C (+14 °F)–20 °C (–4 °F)

0 °C (32 °F)0 °C (32 °F)

–10 °C (+14 °F)–20 °C (–4 °F)

0 °C (32 °F)0 °C (32 °F)

Protection IEC 60529 IP 64 IP 64

Weight Approx. 0.8 kg (1.8 lb) Approx. 0.8 kg (1.8 lb)

* Please indicate when ordering

Sp

ecif

icati

on

s

30

RON 785



• System accuracy ± 2"

Dimensions in mm


31

Incremental

RON 785

Incremental signals � 1 VPP

Line count 18000

Reference mark* RON 785: OneRON 785C: Distance-coded

Cutoff frequency –3dB � 180 kHz

Recommended

measuring step

0.0001°

System accuracy ± 2"

Power supply 5 V ± 10%/max. 150 mA


Max. cable length 150 m

Mech. permissible speed Max. 1000 rpm

Starting torque � 0.5 Nm at 20 °C (68 °F)

Moment of inertia of rotor 1.05 · 10–3kgm2

Natural frequency � 1000 Hz


of measured shaft

± 0.1 mm


� 100 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

Max. operating

temperature

50 °C (122 °F)

Min. operating

temperature

0 °C (32 °F)

Protection IEC 60529 IP 64

Weight Approx. 2.5 kg (5.5 lb)


�

�


RON/RCN 700 Series




32

Dimensions in mm

33


RON 786 RCN 727

Incremental signals � 1 VPP � 1 VPP

Line count* 1800036000

32768


–

Cutoff frequency –3dB � 180 kHz � 180 kHz



Electrically permissiblespeed for position value

– 300 rpm

Recommended

measuring step

0.0001° 0.0001°

System accuracy ± 2" ± 2"

Power supply 5 V ± 10%/max. 150 mA (without load) 5 V ± 5%/max. 350 mA (without load)


Cable 1 m, radial, also usable axially;with coupling

Max. cable length 150 m 150 m



Moment of inertia of rotor 1.2 · 10–3kgm2 1.2 · 10–3kgm2

Natural frequency � 1000 Hz � 1000 Hz


of measured shaft

± 0.1 mm ± 0.1 mm


� 100 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

� 100 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

Max. operating

temperature

50 °C (122 °F) 50 °C (122 °F)

Min. operating

temperature

0 °C (32 °F) 0 °C (32 °F)




RON/RPN/RCN 800 Series




Dimensions in mm

�

�

34


35


RON 886 RPN 886 RCN 827

Incremental signals � 1 VPP � 1 VPP

Line count 36000 90000 (180000 signal periods) 32768


One –

Cutoff frequency –3dB–6dB

� 180 kHz–

� 800 kHz� 1300 kHz

� 180 kHz–



Electrically permissiblespeed for position value

– 300 rpm

Recommended

measuring step

0.00005° 0.00001° 0.0001°


Power supply 5 V ± 10%/max. 150 mA (without load)

5 V ± 10%/max. 250 mA (without load)



Cable 1 m, radial,also usable axially;with or without coupling




Moment of inertia of rotor 1.2 · 10–3 kgm2 1.2 · 10–3 kgm2

Natural frequency � 1000 Hz � 500 Hz � 1000 Hz


of measured shaft

± 0.1 mm ± 0.1 mm


� 100 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

� 50 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

� 100 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

Max. operating

temperature

50 °C (122 °F) 50 °C (122 °F)

Min. operating

temperature

0 °C (32 °F) 0 °C (32 °F)




36

RON 905


• Blind hollow shaft

• System accuracy ± 0.4"


Dimensions in mm

37

Incremental

RON 905

Incremental signals � 11 µAPP

Line count 36000

Reference mark One


Recommended

measuring step

0.00001°

System accuracy ± 0.4"


Electrical connection Cable 1 m, radial, with connector





Natural frequency � 350 Hz


of measured shaft

± 0.2 mm


� 50 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

Max. operating

temperature

30 °C (86 °F)

Min. operating

temperature

10 °C (50 °F)


Weight Approx. 4 kg (8.8 lb)

38

ROD 200 Series

• For separate shaft coupling


� = Bearing

Dimensions in mm

39

Incremental

ROD 260 ROD 270 ROD 280

Incremental signals � TTL � TTL with 10-fold interpolation � 1 VPP

Line count 18000

Reference mark* One ROD 280: OneROD 280C: Distance-coded

Output frequencyCutoff frequency –3dB

Max. 1 MHz–

–� 180 kHz

Recommended

measuring step

0.005° 0.0005° 0.0001°

System accuracy ± 5"






Moment of inertia of rotor 20 · 10–6 kgm2

Shaft load Axial: 10 NRadial: 10 N at shaft end


� 100 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

Max. operating

temperature

70 °C (158 °F)

Min. operating

temperature

Moving cableRigid cable

–10 °C (+14 °F)–20 °C (–4 °F)




40

ROD 780/ROD 880

• For separate shaft coupling

• System accuracy ROD 780: ± 2"

ROD 880: ± 1"

� = Bearing

Dimensions in mm

41

Incremental

ROD 780 ROD 880


Line count* 1800036000

36000

Reference mark* ROD x80: OneROD x80C: Distance-coded


Recommended

measuring step

0.0001° 0.00005°








Shaft load Axial: 30 NRadial: 30 N at shaft end


� 100 m/s2 (IEC 60068-2-6)� 300 m/s2 (IEC 60068-2-27)

Max. operating

temperature

50 °C (122 °F)

Min. operating

temperature

0 °C (32 °F)




42

� = Disk-to-scanning-reticle gap� = Required mating dimensions� = Space needed for service� = Seal = Axis of bearing rotation

Scanning position A

ERP 880

• Modular angle encoder

• High accuracy due to interferential

scanning principle

Dimensions in mm

43

Incremental

ERP 880


Line count 90000 (180000 signal periods)

Reference mark One

Cutoff frequency –3dB–6dB

� 800 kHz� 1.3 MHz

Recommended

measuring step

0.00001°

System accuracy1) ± 1"


Electrical connection With housing: Cable 1 m, radial, also usable axially; with couplingWithout housing: Via 12-pin PCB connector (adapter cable Id. Nr. 372164-xx)


Hub inside diameter 51.2 mm




of measured shaft

± 0.05 mm


� 50 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

Max. operating

temperature

50 °C (122 °F)

Min. operating

temperature

0 °C (32 °F)

Protection* IEC 60529 Without housing: IP 00 With housing: IP 40 With housing and rotary shaft seal:IP 64

Starting torque – 0.25 Nm

Weight 3.0 kg (6.6 lb) 3.1 kg (6.8 lb) incl. housing

* Please indicate when ordering1) Without installation. Additional error caused by mounting inaccuracy and inaccuracy from the bearing of the measured shaft are not included.

44

ERA 180


• Grating on steel drum

Incremental signals

Reference mark

Cutoff frequency –3dB

Power supply

Electrical connection

Max. cable length

Drum inside diameter*

Drum outside diameter*

Line count

System accuracy1)

Accuracy of the graduation2)

Recommended measuring step

Mech. permissible speed

Moment of inertia of rotor


of measured shaft


Max. operating temperature

Min. operating temperature

Protection* IEC 60529

Weight Scale drum

Protective cover

Scanning headwith cable

ERA 180

ERA 180 with protective cover

45

Incremental

ERA 180

� 1 VPP

One

� 500 kHz


Cable 1 m (3.3 ft) with coupling

150 m

40 mm 80 mm 120 mm 180 mm 270 mm 425 mm 512 mm

80 mm 130 mm 180 mm 250 mm 330 mm 485 mm 562 mm

6000 9000 9000 18000 18000 36000 36000

± 7.5" ± 5" ± 5" ± 4" ± 4" ± 2.5" ± 2.5"

± 5" ± 3" ± 3" ± 3" ± 3" ± 2" ± 2"

0.0015° 0.001° 0.001° 0.0005° 0.0005° 0.0001° 0.0001°

40000 rpm 25000 rpm 18000 rpm 13000 rpm 10000 rpm 7000 rpm 6000 rpm

0.58 · 10–3kgm2 3.45 · 10–3kgm2 11.1 · 10–3kgm2 35.7 · 10–3kgm2 82.6 · 10–3kgm2 281.8 · 10–3kgm2 399.7 · 10–3kgm2

± 0.5 mm (scale drum relative to scanning head)

� 100 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

80 °C (176 °F)

–10 °C (+14 °F)

Without protective cover: IP 00With protective cover and compressed air: IP 40

IP 00

Approx. 0.5 kg(1.1 lb)





Approx. 5 kg(11 lb)

Approx. 5.3 kg(12 lb)

Approx. 0.226 kg(0.498 lb)

Approx. 0.365 kg(0.805 lb)



–

Approx. 0.2 kg (0.44 lb)

* Please indicate when ordering1) Without installation. Additional error caused by mounting inaccuracy and inaccuracy from the bearing of the measured shaft are not included.2) For other errors, see Measuring Accuracy

46

Dimensions in mm

ERA 180

� = Bearing = Mounting surfaces� = Mounting clearance set with spacer foil� = Mounting hole = Back-off thread

Protective cover

47

Scale drum

inside diameter

D1 � D2 D3 D4 D5 D6 D7 � E

40 mm 40 –0.001–0.005

50 64 80 80.4 100 110 – 60

80 mm 80 –0.001–0.005

95 112 130 130.4 150 160 – 85

120 mm 120 –0.001–0.008

140 162 180 180.4 200 210 144° 110

180 mm 180 –0.001–0.008

200 232 250 250.4 270 280 150° 145

270 mm 270 –0.01 290 312 330 – – – – 185

425 mm 425 –0.01 445 467 485 – – – – 262.5

512 mm 512 –0.015 528 544 562 – – – – 301

Scale drum inside diameter

270 mm

425 mm

512 mm

40 mm to 180 mm

�

48

ERM 280

• Modular encoder

• Magnetic scanning principle

� = Bearing� = Mounting distance of 0.10 mm set with spacer foil� = Mounting distance of 0.15 mm set with spacer foil for version starting in mid-2004

Dimensions in mm

D1 D2 D3 E

40 –0.007 50 75.44 43.4

70 –0.008 85 113.16 62.3

80 –0.008 95 128.75 70.1

120 –0.010 135 150.88 81.2

130 –0.012 145 176.03 93.7

180 –0.012 195 257.50 134.5

295 –0.016 310 326.90 169.2

New version:

Scheduled for mid-2004

49

Incremental

ERM 280


Reference mark One

Cutoff frequency –3dB � 200 kHz; as of mid-2004: � 300 kHz


Electrical connection Cable 1 m (3.3 ft) with coupling


Drum inside diameter* 40 mm 70 mm 80 mm 120 mm 130 mm 180 mm 295 mm

Drum outside diameter* 75.44 mm 113.16 mm 128.75 mm 150.88 mm 176.03 mm 257.50 mm 326.90 mm

Line count 600 900 1024 1200 1400 2048 2600

System accuracy1) ± 36" ± 25" ± 22" ± 20" ± 18" ± 12" ± 10"

Accuracy of the

graduation2)

± 14" ± 10" ± 9" ± 8" ± 7" ± 5" ± 4"

Recommended

measuring step

0.003° 0.002° 0.002° 0.002° 0.002° 0.001° 0.001°

Mech. perm. speed

as of mid-200424000 rpm/40000 rpm

20000 rpm/26000 rpm

18000 rpm/22000 rpm

12000 rpm/18000 rpm

10000 rpm/15000 rpm

8000 rpm/10000 rpm

5000 rpm/7000 rpm

Moment of inertia of rotor 0.34 · 10–3

kgm21.6 · 10–3

kgm22.7 · 10–3

kgm23.5 · 10–3

kgm27.7 · 10–3

kgm238 · 10–3

kgm244 · 10–3

kgm2

Perm. axial movement ± 1 mm; as of mid-2004: ± 1.25 mm


� 100 m/s2 (IEC 60068-2-6); as of mid-2004: 400 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

Max. operating

temperature

100 °C (212 °F)

Min. operating

temperature

–10 °C (+14 °F)

Protection IEC 60529 IP 66; as of mid-2004: IP 67

Weight

Scale drum Approx.0.35 kg(0.77 lb)

Approx.0.69 kg(1.52 lb)






Scanning headwith cable

Approx. 0.15 kg (0.33 lb)

* Please indicate when ordering; other versions available upon requestCursive: version available as of mid-20041) Without installation. Additional error caused by mounting inaccuracy and inaccuracy from the bearing of the measured shaft are not included.2) For other errors, see Measuring Accuracy

50

ERO 785


• Circular scale with hub

Hub inside

diameter

Line count E B C

155.1 36000 132 0.05 ±0.02 0.02

102.2 94.5 0.20 ±0.02

47.2 67.35 0.08 ±0.01 0.01

Dimensions in mm

1) Mean graduation diameter� = Bearing = Cutout for mounting� = Position of the reference mark to an integral mounting thread ±2°� = Graduation� = Graduation surface� = Mounting surface� = Flange socket

Hub inside diameter

155.1 mm

102.2 mm

47.2 mm

51

Incremental

ERO 785


Line count 36000

Reference mark One

Cutoff frequency –3dB 180 kHz

Recommended

measuring step

0.0001°

System accuracy1) ± 4.2" ± 3" ± 2.2"

Accuracy of the

graduation2)

± 3.7" ± 2.5" ± 1.7"


Electrical connection Cable 0.3 m (1 ft) with flange socket (male) on mounting base

Max. cable length Max. 150 m

Hub inside diameter* 47.2 mm 102.2 mm 155.1 mm

Mech. permissible speed Max. 8000 rpm Max. 6000 rpm Max. 4000 rpm

Moment of inertia of rotor 620 · 10–6 kgm2 3700 · 10–6 kgm2 26000 · 10–6 kgm2

Perm. axial movement See the tolerance of scanning gap “B” in the dimension drawing


� 100 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

Max. operating

temperature

50 °C (122 °F)

Min. operating

temperature

0 °C (32 °F)


Weight

Scanning unit Approx. 0.185 kg (0.4 lb)

Circular scale with hub 0.46 kg (1.0 lb) 0.87 kg (1.9 lb) 2.6 kg (5.7 lb)

* Please indicate when ordering1) Without installation. Additional error caused by mounting inaccuracy and inaccuracy from the bearing of the measured shaft are not included.2) For other errors, see Measuring Accuracy

52

ERA 700 Series

• Modular angle encoder for inside diameters

• Full-circle and segment versions

Dimensions in mm

ERA 781C Scale tape

* = Max. change during operation� = Bearing� = Required mating dimensions for the scale tape (not to scale)L = Distance of the mounting holes

L1 = Traverse pathL2 = Measuring range in radian measure� = Measuring range in degrees (segment angle)� = Scanning gap (distance between scanning reticle and scale-tape surface)� = Mounting clearance for mounting bracket. Spacer foil 0.5 mm = Scale-tape thickness� = Distance between floor of scale-tape slot and threaded mounting hole� = Distance between mounting surface and scale-tape slot� = View of customer boring� = Cam disk for tensioning the scale tape� = Position of first reference mark� = Notch for removing scale tape (1 x b = 2 mm)

53

Incremental

ERA 780C Full-circle versionERA 781C Segment version, scale-tape mounting with tensioning elements


Reference mark Distance-coded, nominal increment of 1000 grating periods





Scale-slot diameter* 318.58 mm 458.62 mm 573.20 mm 1146.1 mm

Line count

ERA 780C full circle – 36000 45000 90000

ERA 781C segment* 72°: 50003)

144°: 100003)50°: 5000

100°: 10000200°: 20000

160°: 20000 –

Recommended measuring

step

0.0002° 0.0001° 0.00005° 0.00002°

System accuracy1)

ERA 780C full circle – ± 3.5" ± 3.4" ± 3.2"

ERA 781C segment See Measuring Accuracy

Accuracy of the

graduation2)

± 3"


Perm. axial movement ± 0.2 mm


� 100 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

Max. operating

temperature

50 °C (122 °F) (thermal coefficient of expansion of the scale substrate between 9 · 10–6K–1 and 12 · 10–6K–1)

Min. operating

temperature

–10 °C (+14 °F)


Weight


Scale tape 30 g/m (7.1 oz/m)

* Please indicate when ordering; other versions available upon request1) Without installation. Additional error caused by mounting inaccuracy and inaccuracy from the bearing of the measured shaft are not included.2) For other errors, see Measuring Accuracy3) Corresponds to 25000 lines on a full circle

54

ERA 800 Series

• Modular angle encoder for outside diameters

• Full-circle and segment versions

ERA 880C Full-circle version

ERA 881C Circle-segment version,scale tape secured with tensioning elements

ERA 882C Circle-segment version,scale tape without tensioning elements

55

Incremental

ERA 880C Full-circle versionERA 881C Segment version, scale-tape mounting via tensioning elementsERA 882C Segment version, scale tape without tensioning elements


Reference mark Distance-coded, nominal increment of 1000 grating periods





Scale-slot diameter* 317.99 mm 458.04 mm 572.63 mm

Line count

ERA 880C full circle – 36000 45000

ERA 881C/

ERA 882C segment*72°: 50003)

144°: 100003)50°: 5000

100°: 10000200°: 20000

160°: 20000

Recommended

measuring step

0.0002° 0.0001° 0.00005°

System accuracy1)

ERA 880C full circle – ± 3.5" ± 3.4"

ERA 881C/

ERA 882C segmentSee Measuring Accuracy

Accuracy of the

graduation2)

± 3"


Perm. axial movement ± 0.2 mm


� 100 m/s2 (IEC 60068-2-6)� 1000 m/s2 (IEC 60068-2-27)

Max. operating

temperature

50 °C (122 °F) (thermal coefficient of expansion of the scale substrate between 9 · 10–6K–1 and 12 · 10–6K–1)

Min. operating

temperature

–10 °C (+14 °F)


Weight


Scale tape 30 g/m (7.1 oz/m)

* Please indicate when ordering; other versions available upon request1) Without installation. Additional error caused by mounting inaccuracy and inaccuracy from the bearing of the measured shaft are not included.2) For other errors, see Measuring Accuracy3) Corresponds to 25000 lines on a full circle

56

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ERA 800 Series

Dimensions in mm

* = Max. change during operation� = Bearing� = Required mating dimensions for scale-tape slot (not to scale)� = Scanning gap (distance between scanning reticle and scale-tape surface)� = Mounting clearance for mounting bracket. Spacer foil 0.5 mm = Scale-tape thickness� = Distance between floor of scale-tape slot and threaded mounting hole� = Distance between mounting surface and scale-tape slot

ERA 880C Scale tape

57

��

ERA 882C Scale tape

ERA 881C Scale tape

* = Max. change during operation� = Bearing� = View of customer boring� = Position of first reference markL = With ERA 881C: Positions of the tensioning elements

= With ERA 882C: Distance of mounting holesL1 = Traverse pathL2 = Measuring range in radian measure� = Measuring range in degrees (segment angle)

58

Interfaces

Incremental Signals � 1 VPP

HEIDENHAIN encoders with � 1 VPPinterface provide voltage signals that canbe highly interpolated.

The sinusoidal incremental signals A and Bare phase-shifted by 90° elec. and have anamplitude of typically 1 VPP. The illustratedsequence of output signals—with B laggingA—applies for the direction of motionshown in the dimension drawing.

The reference mark signal R has a usablecomponent G of approx. 0.5 V. Next to thereference mark, the output signal can bereduced by up to 1.7 V to an idle level H.This must not cause the subsequentelectronics to overdrive. In the loweredsignal level, signal peaks can also appearwith the amplitude G.

The data on signal amplitude apply whenthe power supply given in the specificationsis connected to the encoder. They refer toa differential measurement at the 120 ohmterminating resistor between the associatedoutputs. The signal amplitude decreaseswith increasing frequency. The cutoff

frequency indicates the scanning frequencyat which a certain percentage of the originalsignal amplitude is maintained:• –3 dB cutoff frequency:

70 % of the signal amplitude• –6 dB cutoff frequency:

50 % of the signal amplitude

Interpolation/resolution/measuring step

The output signals of the 1 VPP interfaceare usually interpolated in the subsequentelectronics in order to attain sufficientlyhigh resolutions. For velocity control,

interpolation factors are commonly over1000 in order to receive usable velocityinformation even at low speeds.

Measuring steps for position measurement

are recommended in the specifications. Forspecial applications, other resolutions arealso possible.

Signal period360° elec.

(Rated value)

A, B, R measured with an oscilloscope in differential mode

Sig

nalam

plitu

de

[%]

–3dB cutoff frequency–6dB cutoff frequency Scanning frequency [kHz]

Cutoff frequency

Typical signalamplitude curvewith respect to thescanning frequency

Interface Sinusoidal voltage signals � 1 VPP

Incremental signals Two nearly sinusoidal signals A and B

Signal amplitude M: 0.6 to 1.2 VPP; 1 VPP typicalAsymmetryIP – NI/2M: � 0.065Amplitude ratio MA/MB: 0.8 to 1.25Phase angle I�1 + �2I/2: 90° ± 10° elec.

Reference mark

signal

One or more signal peaks R

Usable component G: 0.2 to 0.85 VQuiescent value H: 0.04 V to 1.7 VSwitching threshold E, F: � 40 mVZero crossovers K, L: 180° ± 90° elec.

Connecting cable

Cable lengthPropagation time

HEIDENHAIN cable with shieldingPUR [4(2 · 0.14 mm2) + (4 · 0.5 mm2)]Max. 150 m distributed capacitance 90 pF/m6 ns/m

Any limited tolerances in the encoders are listed in the specifications.

59

12-pin

HEIDENHAIN

coupling

12-pin

HEIDENHAIN

connector

15-pin D-sub connector,

female,

for HEIDENHAIN controls

and IK 220

12-pin

PCB connector

on ERP 880

Power supply Incremental signals Other signals

12 2 10 11 5 6 8 1 3 4 7 9

1 9 2 11 3 4 6 7 10 12 14 5/8/13/15

2a 2b 1a 1b 6b 6a 5b 5a 4b 4a 3a 3b

UP Sensor

UP

0 V Sensor

0 VA+ A– B+ B– R+ R– Vacant Vacant

Brown/Green

Blue White/Green

White Brown Green Gray Pink Red Black Violet –

Shield is on housing; UP = Power supplySensor: The sensor line is connected internally to the respective the power supply.Vacant pins or wires must not be used!

Ele

ctr

icalC

on

necti

on

s

Input circuitry of the subsequent

electronics

Dimensioning

Operational amplifier MC 34074Z0 = 120 �

R1 = 10 k� and C1 = 100 pFR2 = 34.8 k� and C2 = 10 pFUB = ±15 VU1 approx. U0

–3dB cutoff frequency of circuitry

Approx. 450 kHzApprox. 50 kHz with C1 = 1000 pF

and C2 = 82 pFThis circuit variant does reduce thebandwidth of the circuit, but in doing so itimproves its noise immunity.

Circuit output signals

Ua = 3.48 VPP typicalGain 3.48

Signal monitoring

A threshold sensitivity of 250 mVPP is to beprovided for monitoring the 1 VPP incrementalsignals.

Incremental

signals

Reference mark

signal

Ra < 100 �,approx. 24 �

Ca < 50 pF�Ia < 1 mAU0 = 2.5 V ±0.5 V(with respect to 0 V ofthe power supply)

1 VPP

Subsequent electronicsEncoder

Pin Layout

60

Line count/

Interpolation

Measuring

step1)

Scanning

frequency

Elec. perm.

speed

Min. edge

separation2)

a

RON 225 9000/2-fold 0.005° 500 kHz 3000 rpm(due tomechanics)

0.125 µs

ROD 260 18000/none 0.005° 1 MHz

RON 275 18000/5-fold 0.001° 50 kHz 166 rpm 0.98 µs

RON 275

ROD 270

18000/10-fold 0.0005° 100 kHz 333 rpm 0.23 µs

1) After 4-fold evaluation 2) Taking digitizing effects into account

Interfaces

Incremental Signals � TTL

HEIDENHAIN encoders with � TTLinterface incorporate electronics thatdigitize sinusoidal scanning signals with orwithout interpolation.

The incremental signals are transmittedas the square-wave pulse trains Ua1 and Ua2,phase-shifted by 90° elec. The reference

mark signal consists of one or morereference pulses Ua0, which are gated withthe incremental signals. In addition, theintegrated electronics produce their inverse

signals �, and � for noise-prooftransmission. The illustrated sequence ofoutput signals—with Ua2 lagging Ua1—applies for the direction of motion shownin the dimension drawing.

The fault-detection signal � indicatesfault conditions such as breakage of thepower line or failure of the light source. Itcan be used for such purposes as machineshut-off during automated production.

The distance between two successiveedges of the incremental signals Ua1 andUa2 through 1-fold, 2-fold or 4-foldevaluation is one measuring step.

The subsequent electronics must bedesigned to detect each edge of the square-wave pulse. The minimum edge separa-

tion a listed in the Specifications applies forthe illustrated input circuitry with a cablelength of 1 m, and refers to a measurementat the output of the differential line receiver.Propagation-time differences in cablesadditionally reduce the edge separation by0.2 ns per meter of cable length. To preventcounting error, design the subsequentelectronics to process as little as 90% ofthe resulting edge separation. The max.permissible shaft speed or traversing

velocity must never be exceeded.

Interface Square-wave signals � TTL

Incremental signals 2 TTL square-wave signals Ua1, Ua2 and their inverted signals�, �

Reference mark

signal

Pulse widthDelay time

One or more TTL square-wave pulses Ua0 and their inversepulses �

90° elec. (other widths available on request); LS 323: nongated|td| � 50 ns

Fault detection

signal

Pulse width

One TTL square-wave pulse �

Improper function: LOW (on request: Ua1/Ua2 high impedance)Proper function: HIGHtS � 20 ms

Signal level Differential line driver as per EIA standard RS 422UH � 2.5 V at –IH = 20 mAUL � 0.5 V at IL = 20 mA

Permissible load Z0 � 100 � between associated outputs|ILI � 20 mA max. load per outputCload � 1000 pF with respect to 0 VOutputs protected against short circuit to 0 V

Switching times

(10% to 90%)t+ / t– � 30 ns (typically 10 ns)with 1 m cable and recommended input circuitry

Connecting cable


HEIDENHAIN cable with shieldingPUR [4(2 × 0.14 mm2) + (4 × 0.5 mm2)]Max. 100 m (� max. 50 m) with distributed capacitance 90 pF/m6 ns/m

��

!

Signal period 360° elec. Fault

Measuring step after

4-fold evaluation

Inverse signals �, , � are not shown

61

12-pin

HEIDENHAIN

coupling

12-pin

HEIDENHAIN

connector

Power supply Incremental signals Other signals

12 2 10 11 5 6 8 1 3 4 7 9 /

UP Sensor

UP

0 V Sensor

0 VUa1 � Ua2 � Ua0 � � Vacant Vacant

Brown/Green

Blue White/Green

White Brown Green Gray Pink Red Black Violet / Yellow

Shield is on housing; UP = Power supplySensor: The sensor line is connected internally to the respective the power supply.Vacant pins or wires must not be used!

The permissible cable length for trans-mission of the TTL square-wave signals tothe subsequent electronics depends on theedge separation a. It is max. 100 m, or 50 mfor the fault detection signal. This requires,however, that the power supply (seeSpecifications) be ensured at the encoder.The sensor lines can be used to measurethe voltage at the encoder and, if required,correct it with an automatic system (remotesense power supply).

��

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� �

Cab

lele

ng

ths

[m]

without �

with �

Permissible

cable length

with respect to theedge separation

Incremental signals

Reference mark

signal

Fault detection

signal

Subsequent electronicsEncoderInput circuitry of the subsequent

electronics

Dimensioning

IC1 = Recommended differential linereceiversDS 26 C 32 ATOnly for a > 0.1 µs:AM 26 LS 32MC 3486SN 75 ALS 193

R1 = 4.7 k�

R2 = 1.8 k�

Z0 = 120 �

C1 = 220 pF (serves to improve noiseimmunity)

Pin Layout

Edge separation [µs]

62

Input circuitry of subsequent electronics

Data transfer

IC1 = RS 485differential line receiverand driver

C3 = 330 pFZ0 = 120 �

Incremental signals

As a bidirectional interface, the EnDat(Encoder Data) interface for absoluteencoders is capable of producing absolute

position values as well as requesting orupdating information stored in the encoder.Thanks to the serial transmission method

only four signal lines are required. Thetype of transmission (position values orparameters) is selected by mode commandsthat the subsequent electronics send to theencoder. The data are transmitted in

synchronism with the clock signal fromthe subsequent electronics.

Benefits of the EnDat interface

• One interface for all absolute encoders,whereby the subsequent electronics canautomatically distinguish between EnDatand SSI.

• Complementary output of incremental

signals (optional for highly dynamiccontrol loops).

• Automatic self-configuration duringencoder installation, since all informationrequired by the subsequent electronics isalready stored in the encoder.

• Reduced wiring cost

For standard applications, six lines aresufficient.

• High system security through alarmsand messages that can be evaluated in thesubsequent electronics for monitoringand diagnosis. No additional lines arerequired.

• Minimized transmission times throughadaptation of the data word length to theresolution of the encoder and throughhigh clock frequencies.

• High transmission reliability throughcyclic redundancy checks.

• Datum shifting through an offset valuein the encoder.

• It is possible to form a redundant

system, since the absolute value andincremental signals are outputindependently from each other.

Interfaces

Absolute Position Values

Cab

lele

ng

th[m

]

Clock frequency [kHz]

Interface EnDat 2.1 serial bidirectional

Data transfer Absolute position values and parameters

Data input Differential line receiver according to EIA standard RS 485 forCLOCK, CLOCK, DATA and DATA signals

Data output Differential line driver according to EIA standard RS 485 for theDATA and DATA signals

Signal level Differential voltage output > 1.7 V with Z0 = 120 � load*)(EIA standard RS 485)

Code Pure binary code

Ascending

position values

In traverse direction indicated by arrow (see Dimensions)

Incremental Signals � 1 VPP (see Incremental Signals 1 VPP)

Connecting cable


HEIDENHAIN cable with shieldingPUR [(4 x 0.14 mm2) +4(2 x 0.14 mm2) + (4 x 0.5 mm2)]Max. 150 m with 90 pF/m distributed capacitance6 ns/m

*) Terminating and receiver input resistor

Permissible

clock frequency

with respect to

cable lengths

Encoder Subsequent electronics

63

Function of the EnDat Interface

The EnDat interface outputs absolute

position values, optionally makes incre-

mental signals available, and permitsreading from and writing to the memory

in the encoder.

Selecting the transmission type

Position values and memory contents aretransmitted serially through the DATA lines.The type of information to be transmitted isselected by mode commands. Mode

commands define the content of the infor-mation that follows. Every mode commandconsists of 3 bits. To ensure transmissionreliability, each bit is also transmittedinverted. If the encoder detects an erroneousmode transmission, it transmits an errormessage.The following mode commands areavailable:• Encoder transmit absolute position value• Selection of the memory area• Encoder transmit/receive parameters of

the last defined memory area• Encoder transmit test values• Encoder receive test commands• Encoder receive RESET

Parameters

The encoder provides several memoryareas for parameters. These can be readfrom by the subsequent electronics, andsome can be written to by the encodermanufacturer, the OEM, or even the enduser. Certain memory areas can bewrite-protected.

The parameters, which in most casesare set by the OEM, largely definethe function of the encoder and the

EnDat interface. When the encoder isexchanged, it is therefore essential that itsparameter settings are correct. Attempts toconfigure machines without including OEMdata can result in malfunctions. If there isany doubt as to the correct parametersettings, the OEM should be consulted.

Memory Areas

Parameters of the encoder manufacturer

This write-protected memory area containsall information specific to the encoder,

such as encoder type (linear/angular,singleturn/multiturn, etc.), signal periods,number of position values per revolution,transmission format of absolute positionvalues, direction of rotation, maximumpermissible speed, accuracy dependenton shaft speeds, support from warningsand alarms, part number, and serialnumber. This information forms the basisfor automatic configuration.

Parameters of the OEM

In this freely definable memory area, theOEM can store his information. Forexample, the “electronic ID label” of themotor in which the encoder is integrated,indicating the motor model, maximumcurrent rating, etc.

Operating parameters

This area is available to the customer for adatum shift. It can be protected againstoverwriting.

Operating status

This memory area provides detailed alarmsor warnings for diagnostic purposes. Here itis also possible to activate write protection

for the OEM-parameter and operatingparameter memory areas, and interrogateits status.Once activated, the write protection cannotbe reversed.

Monitoring and Diagnostic Functions

Alarms and warnings

The EnDat interface enables comprehensivemonitoring of the encoder without requiringan additional transmission line. An alarm

becomes active if there is a malfunction inthe encoder that is presumably causingincorrect position values. At the same time,an alarm bit is set in the data word. Alarmconditions include:• Light unit failure• Signal amplitude too low• Error in calculation of position value• Power supply too high/low• Current consumption is excessiveWarnings indicate that certain tolerancelimits of the encoder have been reached orexceeded—such as shaft speed or the limitof light source intensity compensationthrough voltage regulation—without implyingthat the measured position values areincorrect. This function makes it possibleto issue preventive warnings in order tominimize idle time. The alarms and warningssupported by the respective encoder aresaved in the “parameters of the encodermanufacturer” memory area.

Reliable data transfer

To increase the reliability of data transfer, acyclic redundancy check (CRC) is performedthrough the logical processing of theindividual bit values of a data word. This5-bit long CRC concludes every transmission.The CRC is decoded in the receiverelectronics and compared with the dataword. This largely eliminates errors causedby disturbances during data transfer.

Block diagram: Absolute encoder with EnDat interface

Incrementalsignals

Absoluteposition value

Operatingstatus

Operatingparameters(e.g., datumshift)

Parameters ofthe encodermanufacturer

Parametersof the OEM

� 1 VPP A

� 1 VPP B

UP Power0 V supply

EnD

atin

terf

ace

Absolute encoder Subsequent

electronics

64

Encoder savesposition value

Position value Cyclic redundancycheck

Subsequent electronicstransmit mode command

Mode command

Interrupted clock

The interrupted clock is intended particularlyfor time-clocked systems such as closedcontrol loops. At the end of the data wordthe clock signal is set to HIGH level. After

10 to 30 µs (tm), the data line falls back toLOW. Then a new data transmission canbegin by starting the clock.

Continuous clock

For applications that require fast acquisitionof the measured value, the EnDat interfacecan have the clock run continuously.Immediately after the last CRC bit has beensent, the DATA line is switched to HIGH forone clock cycle, and then to LOW. Thenew position value is saved with the verynext falling edge of the clock and is output

in synchronism with the clock signalimmediately after the start bit and alarm bit.Because the mode command encodertransmits position value is needed onlybefore the first data transmission, thecontinuous-clock transfer mode reducesthe length of the clock-pulse group by 10periods per position value.

Data transfer

The two types of EnDat data transfer areposition value transfer and parametertransfer.

Control Cycles for Transfer of Position

Values

The clock signal is transmitted by thesubsequent electronics to synchronize thedata output from the encoder. When nottransmitting, the clock signal defaults toHIGH. The transmission cycle begins withthe first falling edge. The measured valuesare saved and the position value calculated.

After two clock pulses (2T), the subsequentelectronics send the mode command

Encoder transmit position value.

After successful calculation of the absoluteposition value (tcal—see table), the start bit

begins the data transmission from theencoder to the subsequent electronics.

The subsequent alarm bit is a commonsignal for all monitored functions and servesfor failure monitoring. It becomes active if amalfunction of the encoder might result inincorrect position values. The exact causeof the trouble is saved in the encoder’s“operating status” memory where it canbe interrogated in detail.

The absolute position value is thentransmitted, beginning with the LSB. Itslength depends on the encoder being used.It is saved in the encoder manufacturer’smemory area. Since EnDat does not needto fill superfluous bits with zeros as in SSI,the transmission time of the position valueto the subsequent electronics is minimized.

Data transmission is concluded with thecyclic redundancy check (CRC).

ROC, ECN,

ROQ, EQN1)

ECI/EQI1)

RCN1)

LC1)

Clock frequency fC 100 kHz to 2 MHz

Calculation time for

Position value

Parameter

tcaltac

250 nsMax. 12 ms

5 µsMax. 12 ms

10 µsMax. 12 ms

1 msMax. 12 ms

Recovery time tm 10 to 30 µs

HIGH Pulse width tHI 0.2 to 10 µs

LOW pulse width tLO 0.2 µs to 50 ms 0.2 to 30 µs1)See also Rotary Encoders, Position Encoders for Servo Drives,1)

Sealed Linear Encoders catalogs

Save newposition value

Position value

Save newposition value

CRCCRC

n = 0 to 5; depending on the system

65

Encoder Subsequent electronics

Latch signal

Counter

Subdivision

Parallelinterface

Co

mp

ara

tor

Control cycles for transfer of parameters

(mode command 001110)

Before parameter transfer, the memoryarea is specified with the mode commandSelect memory area and a subsequentmemory-range-select code (MRS). Thepossible memory areas are stored in theparameters of the encoder manufacturer.Due to internal access times to theindividual memory areas, the time tac mayreach 12 ms.

Reading parameters from the encoder


After selecting the memory area, thesubsequent electronics transmit a completecommunications protocol beginning withthe mode command Encoder transmitparameters, followed by an 8-bit addressand 16 bits with random content. Theencoder answers with the repetition of theaddress and 16 bits with the contents ofthe parameter. The transmission cycle isconcluded with a CRC check.

Writing parameters to the encoder


After selecting the memory area, thesubsequent electronics transmit a completecommunications protocol beginning withthe mode command Encoder receiveparameters, followed by an 8-bit addressand a 16-bit parameter value. The encoderanswers by repeating the address and thecontents of the parameter. The CRC checkconcludes the cycle.

Transmitter in encoder inactive

Receiver in encoder active

Transmitter in encoder active

MRS code

Address

Address

x = random y = parameter Acknowledgment

MRS code

Address

Address

Parameter

8 Bit 16 Bit 8 Bit 16 Bit

Synchronization of the serially

transmitted code value with the

incremental signal

Absolute encoders with EnDat interfacecan exactly synchronize serially transmittedabsolute position values with incrementalvalues. With the first falling edge (latch signal)of the CLOCK signal from the subsequentelectronics, the scanning signals of theindividual tracks in the encoder and counterare frozen, as are also the A/D convertersfor subdividing the sinusoidal incrementalsignals in the subsequent electronics.

The code value transmitted over the serialinterface unambiguously identifies oneincremental signal period. The position valueis absolute within one sinusoidal period ofthe incremental signal. The subdividedincremental signal can therefore beappended in the subsequent electronics tothe serially transmitted code value.

After power on and initial transmission ofposition values, two redundant positionvalues are available in the subsequent elec-tronics. Since encoders with EnDat interfaceguarantee a precise synchronization—regardless of cable length—of the seriallytransmitted absolute value with theincremental signals, the two values can becompared in the subsequent electronics.This monitoring is possible even at highshaft speeds thanks to the EnDat interface’sshort transmission times of less than 50 µs.This capability is a prerequisite for modernmachine design and safety concepts.

1 VPP

1 VPP

66

Pin Layout


male

for IK 115


female,

for HEIDENHAIN controls andIK 220

Power supply Incremental Signals Absolute position values

4 12 2 10 6 1 9 3 11 5 13 8 15

1 9 2 11 13 3 4 6 7 5 8 14 15

UP Sensor

UP

0 V Sensor

0 VInside

shield

A+ A– B+ B– DATA DATA CLOCK CLOCK

Brown/Green

Blue White/Green

White / Green/Black

Yellow/Black

Blue/Black

Red/Black

Gray Pink Violet Yellow

Shield is on housing; UP = power supplySensor: The sensor line is connected internally to the respective power supply.Vacant pins or wires must not be used!

17-pin

HEIDENHAIN

coupling or

flange socket

12-pin PCB connector

Power supply Incremental Signals Absolute position values

7 1 10 4 11 15 16 12 13 14 17 8 9

1b 6a 4b 3a / 2a 5b 4a 3b 6b 1a 2b 5a

UP Sensor

UP

0 V Sensor

0 VInside

shield

A+ A– B+ B– DATA DATA CLOCK CLOCK

Brown/Green

Blue White/Green

White / Green/Black

Yellow/Black

Blue/Black

Red/Black

Gray Pink Violet Yellow

Shield is on housing; UP = power supply; T = temperatureSensor: The sensor line is connected internally to the respective the power supply.Vacant pins or wires must not be used!

67

Flange socket: A flange socket ispermanently mounted on the encoder ormachine housing, has an external thread,and is available with male or femalecontacts.

D-sub connector: D-sub connectors fit onHEIDENHAIN controls and IK countercards.

Coupling: A connecting element withexternal thread, regardless of whether thecontacts are male or female.

Connector: A connecting element withcoupling ring, regardless of whether thecontacts are male or female.

Contacts:

Male contacts

Female contacts

Pin numbering

The pins on connectors are numbered indirections opposite to those on couplings,regardless of whether the contacts aremale or female. Since couplings and flangesockets both have external threads, theyhave the same pin-numbering direction.

Connecting Elements and Cables

General Information

Protection: When engaged, the connections(except D-sub connectors) provide protectionto IP 67 (IEC 60529 / IEC 144). When notengaged, there is no protection (IP 00).

Connector insulated Coupling insulated

Flange socket D-sub connector

x

x: 42.7y: 41.7

y

Coupling on mounting base insulated

68

Connecting Elements and Cables

� 1 VPP and � TTL

Coupling on encoder cable Coupling (male), 12-pin

For encoder cable 6 mm 291698-03

Coupling mounted on encoder cable Mounted coupling

(male), 12-pin

For encoder cable 6 mm 291698-08

Polyurethane (PUR) connecting cable dia. 8 mm

[4(2 x 0.14 mm2) + (4 x 0.5 mm2)]for encoders with coupling

Mating element on connecting cable

to coupling on encoder cable or

flange socket

Connector (female),

12-pin

Complete with connector (female)and connector (male)

298399-xx

For connecting cable 8 mm 291697-05

Complete with connector (female)and D-sub connector (female)15-pin for HEIDENHAIN controlsand IK 220

310199-xx Connector on cable for connectionto subsequent electronics

Connector (male), 12-pin


With one connector (female) 309777-xx Flange socket for connecting cable tosubsequent electronics

Flange socket (female),

12-pin: 315892-08

Coupling on mounting

base (female),

for cable dia. 8 mm,12-pin: 291698-07

Without connectors 244957-01

Adapter cable for ERP 880 dia. 4.5 mm

With one connector

with 12-pin PCB connectorwith shield connection clamp

372164-xx

Adapter connector � 1 VPP/� 11 µAPP

For converting the 1-VPP output signalsto 11-µAPP input signals for thesubsequent electronics; equippedwith connector (female) 12-pin andconnector (male) 9-pin

364914-01

69

Connecting element on encoder

cable

Coupling (male),

17-pin

For encoder cable dia. 4.5 mmdia. 6 mm

291698-25291698-26

Polyurethane (PUR) dia. 8 mm

[(4 x 0.14 mm2) + 4(2 x 0.14 mm2) + (4 x 0.5 mm2)]Mating element on connecting cable

for connecting element on encoder

Connector (female),

17-pin

Complete with connector (female) andD-sub connector (male) for IK 115

324544-xx


Complete with connector (female)and D-sub connector (female) forHEIDENHAIN controls and IK 220.

332115-xx Connector on cable for connection tosubsequent electronics

Connector (male), 17-pin


With one connector (female) 309778-xx Coupling on extension cable Coupling (male),

17-pin


Without connectors 266306-01

EnDat Interface

70

General Electrical Information

Cable

Lengths

The cable lengths listed in the Specificationsapply only for HEIDENHAIN cables and therecommended input circuitry of subsequentelectronics.

Durability

All encoders use polyurethane (PUR) cables.PUR cables are resistant to oil, hydrolysis andmicrobes in accordance with VDE 0472. Theyare free of PVC and silicone and comply withUL safety directives. The UL certification

AWM STYLE 20963 80 °C 30 V E63216 isdocumented on the cable.

Temperature range

HEIDENHAIN cables can be used:for rigid configuration –40 to 85 °Cfor frequent flexing –10 to 85 °C

Cables with limited resistance to hydrolysisand microbes are rated for up to 100 °C.

Bending radius

The permissible bending radii R depend onthe cable diameter and the configuration:

Electrically permissible speed/

Traversing speed

The maximum permissible shaft speed ortraversing velocity of an encoder is derivedfrom• the mechanically permissible shaft

speed/traversing velocity (if listed inSpecifications)and

• the electrically permissible shaft speed/traversing velocity.For encoders with sinusoidal output

signals, the electrically permissible shaftspeed/traversing velocity is limited bythe –3dB/ –6dB cutoff frequency or thepermissible input frequency of thesubsequent electronics.For encoders with square-wave signals,

the electrically permissible shaft speed/traversing velocity is limited by– the maximum permissible scanning/

output frequency fmax of the encoderand

– the minimum permissible edgeseparation a for the subsequentelectronics.

For angular/rotary encoders

nmax =fmax · 60 · 103

For linear encoders

vmax = fmax · SP · 60 · 10–3

wherenmax: Electrically permissible shaft

speed in rpm,vmax: Electrically permissible traversing

velocity in m/minfmax: Maximum scanning/output

frequency of the encoder orinput frequency of thesubsequent electronics in kHz,

z : Line count of the angular/rotary encoder per 360 °

SP : Signal period of the linearencoder in µm

Typically 500 ms

UPP

Initial transient of the

power supply voltage, e.g. 5 V ± 5 %

Power supply

The encoders require a stabilized dc

voltage UP as power supply. The respectivespecifications state the required powersupply and the current consumption. Thepermissible ripple content of the dc voltageis:• High frequency interference

UPP < 250 mV with dU/dt > 5 V/µs• Low frequency fundamental ripple

UPP < 100 mV

The values apply as measured at theencoder, i.e., without cable influences. Thevoltage can be monitored and adjusted withthe device’s sensor lines. If a controllablepower supply is not available, the voltagedrop can be halved by switching the sensorlines parallel to the corresponding powerlines.

Calculation of the voltage drop:

�U = 2 · 10–3 ·

where�U :Line drop in VLC: Cable length in mmI : Current consumption of the

encoder in mA (see Specifications)AV: Cross section of power lines

in mm2

LC · I56 · AV

HEIDENHAIN

cables

Cross section of power lines AV

1 VPP/TTL/HTL 11 µAPP EnDat/SSI

� 3.7 mm 0.05 mm2 – –

� 4.5/5.1 mm 0.14/0.052) mm2 0.05 mm2 0.05 mm2

� 6/101)

mm 0.19/ 0.143) mm2 – 0.08 mm2

� 8/141)

mm 0.5 mm2 1 mm2 0.5 mm2

HEIDENHAIN

cables

Rigid con-

figuration

Frequent

flexing

� 3.7 mm R � 8 mm R � 40 mm

� 4.5 mm

� 5.1 mm

R � 10 mm R � 50 mm

� 6 mm R � 20 mm R � 75 mm

� 8 mm R � 40 mm R � 100 mm

� 10 mm1) R � 35 mm R � 75 mm

� 14 mm1) R � 50 mm R � 100 mm1) Metal armor

2) Only on length gauges3) Only for LIDA 400

zRigid configuration

Frequent flexing

Frequent flexing

71

Reliable Signal Transmission

Electromagnetic compatibility/

CE compliance

When properly installed, HEIDENHAINencoders fulfill the requirements for electro-magnetic compatibility according to89/336/EEC with respect to the genericstandards for:• Noise immunity IEC 61000-6-2:

Specifically:– ESD IEC 61000-4-2– Electromagnetic fields IEC 61000-4-3– Burst IEC 61000-4-4– Surge IEC 61000-4-5– Conducted

disturbances IEC 61000-4-6– Power frequency

magnetic fields IEC 61000-4-8– Pulse magnetic fields IEC 61000-4-9

• Interference IEC 61000-6-4:

Specifically:– For industrial, scientific and medical

(ISM) equipment IEC 55011– For information technology

equipment IEC 55022

Transmission of measuring signals—

electrical noise immunity

Noise voltages arise mainly throughcapacitive or inductive transfer. Electricalnoise can be introduced into the systemover signal lines and input or outputterminals. Possible sources of noise are:• Strong magnetic fields from transformers

and electric motors• Relays, contactors and solenoid valves• High-frequency equipment, pulse

devices, and stray magnetic fields fromswitch-mode power supplies

• AC power lines and supply lines to theabove devices

Isolation

The encoder housings are isolated againstall circuits.Rated surge voltage: 500 V(preferred value as per VDE 0110 Part 1)

Protection against electrical noise

The following measures must be taken toensure disturbance-free operation:• Use only original HEIDENHAIN cables.

Watch for voltage attenuation on thesupply lines.

• Use connectors or terminal boxes withmetal housings. Do not conduct anyextraneous signals.

• Connect the housings of the encoder,connector, terminal box and evaluationelectronics through the shield of thecable. Connect the shielding in the areaof the cable inlets to be as induction-freeas possible (short, full-surface contact).

• Connect the entire shielding system withthe protective ground.

• Prevent contact of loose connectorhousings with other metal surfaces.

• The cable shielding has the function ofan equipotential bonding conductor. Ifcompensating currents are to be expectedwithin the entire system, a separateequipotential bonding conductor must beprovided.See also EN 50178/ 4.98 Chapter 5.2.9.5regarding “protective connection lineswith small cross section.”

• Connect HEIDENHAIN position encodersonly to subsequent electronics whosepower supply is generated through doubleor strengthened insulation against linevoltage circuits. See also IEC 364-4-41:

1992, modified Chapter 411 regarding“protection against both direct and indirecttouch” (PELV or SELV).

• Do not lay signal cables in the directvicinity of interference sources (inductiveconsumers such as contacts, motors,frequency inverters, solenoids, etc.).

• Sufficient decoupling from interference-signal-conducting cables can usually beachieved by an air clearance of 100 mm(4 in.) or, when cables are in metal ducts,by a grounded partition.

• A minimum spacing of 200 mm (8 in.) toinductors in switch-mode power suppliesis required. See also EN 50178 /4.98Chapter 5.3.1.1 regarding cables andlines, EN 50174-2 /09.01, Chapter 6.7regarding grounding and potentialcompensation.

• When using multiturn encoders in

electromagnetic fields greater than10 mT, HEIDENHAIN recommendsconsulting with the main facility inTraunreut.

Both the cable shielding and the metalhousings of encoders and subsequentelectronics have a shielding function. Thehousings must have the same potential

and be connected to the main signal groundover the machine chassis or by means of aseparate potential compensating line.Potential compensating lines should have aminimum cross section of 6 mm2 (Cu).

Minimum distance from sources of interference

72

Evaluation and Display Units

ND 281B

Position display unit

The ND 281B position display unit containsspecial display ranges for angle measure-ment. You can directly connect incrementalangle encoders with � 1-VPP output sig-nals and any line count up to 999999 signalperiods per revolution. The display value isavailable via the RS-232-C/V.24 interface forfurther processing or print-out.

ND 281B

Input signals � 1 VPP � 11 µAPP

Encoder inputs Flange socket, 12-pin female Flange socket, 9-pin female

Input frequency Max. 500 kHz Max. 100 kHz


Signal subdivision Up to 1024-fold (adjustable)

Display step

(adjustable)Decimal degrees: 0.1° to 0.000002°Degrees, minutes, seconds: to 1"

Display range

(adjustable)0 to 360°–180° .... 0 ..... +180°0 to ± max. display range

Features Sorting and tolerance check mode with two limit valuesDisplay stopTwo switching limitsReference-mark evaluation with REF

External operation Zero reset, preset and latch command

Interface RS-232-C/V.24; max. 38400 baud

IBV 600 series

Interpolation and digitizing electronics

Interpolation and digitizing electronicsinterpolate and digitize the sinusoidal outputsignals (� 1 VPP) from HEIDENHAINencoders up to 400-fold, and convert themto TTL square-wave pulse sequences.

IBV 610 IBV 650 IBV 660

Input signals � 1 VPP

Encoder inputs Flange socket, 12-pin female

Interpolation (adjustable) 5-fold10-fold

50-fold 25-fold50-fold

100-fold200-fold400-fold

Input frequency/

minimum edge separation

(adjustable)

5-fold interpolation200 kHz/0.25 µs100 kHz/0.5 µs50 kHz/1 µs25 kHz/2 µs

10-fold interpolation200 kHz/0.125 µs100 kHz/0.25 µs50 kHz/0.5 µs25 kHz/1 µs

40 kHz/0.125 µs20 kHz/0.25 µs10 kHz/0.5 µs5 kHz/1 µs

Depending oninterpolation:100 kHz/0.1 µsto0.78 kHz/0.8 µs

Output signals • Two TTL square-wave pulse trains Ua1 and Ua2and their inverted signals � and

• Reference pulse Ua0 and �

• Interference signal �

Power supply 5 V ± 5%For more information, see the Interpolationand Digitizing Electronics catalog.

For more information, see the NumericalDisplays for Length and Angle catalog.

73

IK 220

Universal PC counter card

The IK 220 is an expansion board for AT-compatible PCs for recording the measuredvalues of two incremental or absolute

linear or angle encoders. The subdivisionand counting electronics subdivide thesinusoidal input signals to generate up to4096 measuring steps per input signalperiod. A driver software package isincluded in delivery.

IK 220

Input signals

(switchable)� 1 VPP � 11 µAPP EnDat SSI

Encoder inputs 2 D-sub connectors (15-pin), male

Input frequency (max.) 500 kHz 33 kHz –

Cable lengths (max.) 60 m 10 m

Signal subdivision

(signal period: meas. step) Up to 4096-fold

Data register for measured

values (per channel)48 bits (44 bits used)

Internal memory For 8192 position values

Interface PCI bus (plug and play)

Driver software and

demonstration program

For WINDOWS NT/95/98

in VISUAL C++, VISUAL BASIC andBORLAND DELPHI

Dimensions Approx. 190 mm × 100 mmFor more information, see the IK 220product information sheet.

Ele

ctr

on

ics

74

head needs to be aligned very accuratelyduring mounting. HEIDENHAIN offersvarious measuring and testing equipmentfor checking the quality of the output signals.

With modular angle encoders the scanninghead moves over the graduation withoutmechanical contact. Thus, to ensurehighest quality output signals, the scanning

PWT 18

Encoder input 1 VPP

Features Measuring the signal amplitudeTolerance of signal shapeAmplitude and position of the reference-mark signal

Power supply Via power supply unit (included)

Dimensions 114 mm x 64 mm x 29 mm

for Absolute Angle Encoders

The PWM 9 is a universal measuring devicefor checking and adjusting HEIDENHAINincremental encoders. There are differentexpansion modules available for checkingthe different encoder signals. The valuescan be read on an LCD monitor. Soft keysprovide ease of operation.

IK 115

Encoder input EnDat (absolute value or incremental signals) or SSI

Interface ISA bus

Application software Operating system: Windows 95/98Functions: Position value display

Counter for incremental signalsEnDat functions

Dimensions 158 mm x 107 mm

The PWT 18 is a simple adjusting aid forHEIDENHAIN incremental encoders. In asmall LCD window the signals are shownas bar charts with reference to theirtolerance limits.

The IK 115 is an adapter card for PCs forinspecting and testing absoluteHEIDENHAIN encoders with EnDat or SSIinterface. Parameters can be read andwritten via the EnDat interface.

HEIDENHAIN Measuring Equipment

for Incremental Angle Encoders

PWM 9

Inputs Expansion modules (interface boards) for 11 µAPP; 1 VPP;TTL; HTL; EnDat*/SSI*/commutation signals*No display of position values or parameters

Features • Measures signal amplitudes, current consumption,operating voltage, scanning frequency

• Graphically displays incremental signals, (amplitudes,phase angle and on-off ratio) and the reference mark signal(width and length)

• Display symbols for reference mark, fault detectionsignal, counting direction

• Universal counter, interpolation selectablefrom 1 to 1024-fold

• Adjustment aid for exposed encoders

Outputs • Inputs are fed through for subsequent electronics• BNC sockets for connection to an oscilloscope

Power supply 10 to 30 V, max 15 W

Dimensions 150 mm × 205 mm × 96 mm

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