Rockwell Automation 1770-KF2 Data Highway or Highway Plus Interface Module User Manual User Manual

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Message Packet Formats

Chapter 5

5-21

Note that the interface module at the receiving PC station executes this
command by first making a copy of the addressed PC byte. It then sets or
resets the appropriate bits and writes the byte back into PC memory. At
the same time, the PC processor can be changing the states of the original
bits in memory. Because of this, some data bits may unintentionally be
overwritten.

Command Format:

Reply Format:

TNS

STS

CMD

SRC

DST

TNS

STS

CMD

SRC

DST

ADDR

Up to 60 Masks of This Form

SET

RESET

Unprotected Read

This command reads words of data from any area of PC data table
memory. Use the SIZE field to specify the number of bytes to be read.
To specify a number of PC words, SIZE should be an even value because
PC words are two bytes long.

Command Format:

Reply Format:

TNS

STS

CMD

SRC

DST

TNS

STS

CMD

SRC

DST

ADDR

DATA — Max. of 244 Bytes

SIZE