Rockwell Automation 1775-KA PLC-3 Communication Adapter Module User Manual - Manual (Page 183)

Message Formats
Appendix A
AĆ21
Privileged Write
Use this write command with a PLC–3 physical address as a starting
address. You use this command to download to a PLC–3 from a
computer. The destination 1775– KA module will accept this command
only after the source station has successfully transmitted a shutdown
request. The function code for this command is 8.
Command Format:
DLE SRC C
0
S TNS MD
F
TS TNS STX FNC
08
DST
DLE ETX BCC DATA - Max of 238 bytes or 119 words
PLC-3
physical address
Reply Format:
This is the same as the reply packet format for all writes.
A. Format when the command was successfully executed
DLE SRC STX DST C
4F
S TNS
MD TS TNS DLE ETX BCC
B. Format when reporting an error
ETX
STS
DLE SRC STX DST C
4F
S TNS
MD TS TNS DLE ETX BCC
Where the extended status byte is optional.
From a computer you use this command to ask the 1775–KA module to
initiate either a PLC–3 shutdown (if the computer has download
privileges) or a freeze on file allocations (if the computer has upload
privileges). This command halts program and I/O scanning. You cannot
issue this command until you have successfully transmitted an upload or
download request to the 1775–KA module. This command has a function
code of 7.