Ać13 – Rockwell Automation 1775-KA PLC-3 Communication Adapter Module User Manual User Manual

Page 175

Message Formats

Appendix A

AĆ13

PLC–3 stations can receive any of the commands in the basic command
set and execute them within a specified file in the PLC–3 memory. They
can also execute the following commands, which apply only to PLC–3
controllers:

bit write
word range read
word range write
file read
file write

Only a computer can send privileged commands. Their primary use is for
uploading and downloading PLC–3 memory.

Only a computer or another PLC–3 station can initiate the non–privileged
PLC–3 commands listed above. Their primary use is for transferring data
between two PLC–3 files. Those files may be located in the same PLC–3
processor or in two different PLC–3’s

Bit Write

Use this bit write command to modify the bits at the address specified by
either a word symbol, a file symbol plus a word offset, or a logical
address. This write command can write a block of data. This address
must point to a word within a file. The function code is 2. Unlike the
unprotected and protected bit writes in the basic command set, this
command can be used to change the bits in a single word only.

Command Format:

A. Word symbol address

DLE

SRC

TNS

STX

FNC

ASCII sumbol

(8 characters max)

DLE ETX

BCC

W/F

SET

RESET

Mask

PLC-3 Commands