ascii,computer and network interface

8/8/2019 Ascii,Computer and Network Interface

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ASCII,COMPUTER ASCII,COMPUTER

AND NETWORK AND NETWORK INTERFACEINTERFACE


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ASCII CODE ASCII CODE

stands forstands for A A mericanmerican SStandardtandard CCode forode forIInformationnformation II nterchange.nterchange.

It is anIt is an alphanumeric codealphanumeric code because it includes because it includes letterslettersas well asas well as numbersnumbers ..

It is used to interface theIt is used to interface the PLC CPUPLC CPU with withalphanumericalphanumeric keyboardskeyboards andand printersprinters ..


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ASCII codes includes: ASCII codes includes:

26 lowerlower case.

26 upperupper case.

25 special charactersspecial characters[@,#,$,%,*,+.-.(,= and so on].


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Process of ASCIIProcess of ASCII :

The key on the keyboard of a computer areconverted directly into ASCII for processing by thecomputer.

Each time you press a keyboard, a 7 bit or 8-bit wordstored in the computer memory to represent by thealphanumeric, function, or control data represented by the specific key that was depressed.

ASCII modules convert the ASCII code informationto PLC can process information.


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The communication interfacing is done througheither an RSRS--232 or RS232 or RS--422 protocol422 protocol .Modules are available that will transmit and receive

ASCII files and that can be used to create an operatorinterface.The user writes a program in the BASIC languagethat operates in conjunction with the ladder logic asthe program runs.


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FUZZY LOGIC INTERFACEFUZZY LOGIC INTERFACE


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Fuzzy logic inter Fuzzy logic interfacesfaces, which are offered by a few PLC, which are offered by a few PLCmanufacturers, provide a way of manufacturers, provide a way of implementingimplementing fuzzyfuzzylogic algorithms inlogic algorithms in PLCsPLCs ..Fuzzy logic algorithmsFuzzy logic algorithms analyseanalyse input data to provideinput data to provide

controlcontrol of aof a process. process.TheyThey work with other input and output interfaces,work with other input and output interfaces,

providing an providing an intelligent link between the two.intelligent link between the two.


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NETWORK INTERFACING MODULE NETWORK INTERFACING MODULE


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ItsIts allow a number of PLCs and otherallow a number of PLCs and other intelligentintelligent

devices to communicatedevices to communicate and passand pass PLC data over aPLC data over ahigh speedhigh speed local area communicationlocal area communication network network ..

Any Any device may interface withdevice may interface with the network.the network.

Because, TheBecause, The network isnetwork is not restrictednot restricted to only to only products designed by theproducts designed by the networksnetworks manufacturer.manufacturer.


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MOST POPULAR NETWORKS:MOST POPULAR NETWORKS:

DeviceDevice--levellevel bus networks bus networks (e.g.,(e.g., CAN bus,CAN bus, Seriplex,Seriplex,etc.), which are used by discrete devicesetc.), which are used by discrete devicesProcessProcess field networksfield networks (e.g., Fieldbus and(e.g., Fieldbus and ProfibusProfibus),),

which are used by analog devices which are used by analog devicesEthernet/IEEEEthernet/IEEE 802.3 networks802.3 networks , used by PLC, used by PLCCPUsCPUs and computersand computersProprietary Proprietary networksnetworks , which are widely used, which are widely used by by large PLC manufacturerslarge PLC manufacturers


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A standard PLC local area A standard PLC local area network:network:


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A A PLC local area network withPLC local area network with CAN busCAN bus (device bus) and Fieldbus(device bus) and Fieldbus(process bus)(process bus) sub networks:sub networks:


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A network interface module implements all of the

necessary communication connections andprotocols to ensure that a message is accurately passed along the network.

network interface transmits the message over thenetwork at the networks baud rate speed.

The speed and protocol for the communication link varies depending on the network .


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COMMUNICATION MEDIA:COMMUNICATION MEDIA:

twin axial.coaxial.twisted-pair.

Depending on the network type and configuration, anetwork module can be connected, at a distance of up to 10,000 feet, with 100 to 1000 devices (nodes).


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ascii,computer and network interface

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