using modbus communication to control step motors
DESCRIPTION
Learn about the popular Modbus industrial communication standard and how it can be used to control step motorsTRANSCRIPT
October 9, 2013
Jeff Kordik
Development, Application Support & Marketing Concepts
2Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
Why Modbus?
Modbus is a standard data transfer protocol that is supported by many PLCs and HMIs
By supporting Modbus on our products, applications using PLCs or HMIs can easily
• command motion• query status• set drive parameters• launch Q segments
3Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
How does it work?
PLC is the master, drive is the slave Internal PLC or HMI memory is first loaded with
parameters to be sent to Modbus registers in the drive The drive (slave) address is specified The data range to transfer (how many bytes and what
location) is then set and the data is transferred• Is it a good idea to have related functions mapped to adjacent
register addresses• For example: speed, accel, decel and distance
4Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
Two Kinds of Modbus
Modbus/RTU Family:• STM17/23/24• SWM24• ST5/10• STAC6
Target Launch Date: December, 2013 Modbus/TCP in early 2014
• STM23/24• SWM24• ST• STAC5
RS-232/485
Ethernet
5Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
About Modbus
Modbus standards are established by The Modbus Organization
Applied Motion Products is a proud member of The Modbus Organization
6Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
Modbus Stepper Products
These Modbus-enabled products were introduced to the market on December 20, 2013
STM24QF integrated step drive+motor• Available with RS-232 or RS-485 communication• Stored Q programming capability for distributed
intelligence
SWM24QF integrated step drive+motor• IP65 rated for harsh environments• Available with RS-232 communication• Stored Q programming capability for distributed
intelligence
Encoder feedback for closed loop
control
7Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
Modbus Data Transfer Example
Step 1: Setting up a Point to Point Move
Accel rateV1300
Decel rateV1301
SpeedV1302
DistanceV1303/4
Accel rate 40001
Decel rate 40002
Speed 40003
Distance 40004/5
PLC memory Modbus registers SCL register mapping
AC
DE
VE
DI
PLC DSP
RS-232RS-485
OrEthernet
8Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
Modbus Data Transfer Example
Step 2: Starting a Point to Point Move
CommandV1305 Command 40006
PLC memory Modbus registers SCL register mapping
FL
PLC DSP
RS-232RS-485
OrEthernet
Command register will contain a bit for each type of move:FL, FP, SH, FS, FE, CJ etc
And other commands such as:ST, SJ
9Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
PLC Program (Ladder Logic)
10Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
PLC Program (Ladder Logic)
11Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
Modbus
Application Support Objective: make sure our products are easy to apply with the most popular and cost effective PLCs and HMIs
Marketing Objective: engage our channel partners to pair our controls with their PLCs and HMIs
Popular Modbus PLCs in North America
13Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
Schneider/Modicon
Modicon, invented Modbus Owned by Schneider One of world’s best selling
PLC lines
14Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
Automation Direct/Direct Logic
Popular online automation retailer
Have own PLC line, lowest cost
Application note for controlling Applied Motion Products Modbus drives by Jeff Kordik is available at http://www.applied-motion.com/support/application-notes
15Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
Omron
Making big push into U.S. market
July 2013: introduced “Easy Modbus Master”
Popular Modbus HMIs in North America
17Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
Proface
Sold by many Applied Motion channel partners
Powerful color touchscreen HMI with RS-232 and Ethernet
Application note for controlling Applied Motion Products Modbus drives by Jeff Kordik is available at http://www.applied-motion.com/support/application-notes
18Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
Beijer
Sold by many Applied Motion channel partners
Powerful color touchscreen HMI with RS-232 and Ethernet
Application note for controlling Applied Motion Products Modbus drives by Jennifer Gaona is available at http://www.applied-motion.com/support/application-notes
19Applied Motion Products Confidential and Proprietary
Reproduction by any method or unauthorized circulation is prohibited without prior approval.
Automation Direct
Popular online automation retailer
EA1-T6CL 6” color touchscreen HMI is a good value.
Application note for controlling Applied Motion Products Modbus drives by Jeff Kordik is available at http://www.applied-motion.com/support/application-notes