Rockwell Automation 1775-S5_SR5,D17756.5.5 User Manual PLC-3 FAMILY I/0 - Manual (Page 147)

Binary Command Language
Appendix A
A-19
A success code returns when the number of data words returned equals the
number requested. For example:
STX
02
OSC
01
SIZ
06
RSP
00 02 04
DAT
03 0F 02
ETX
03
CHK
26
The data bytes store:
size byte (02 hex)
lower byte of the first data word (04 hex)
upper byte of the first data word (03 hex)
lower byte of the second data word (0F hex)
upper byte of the second data word (02 hex)
A size too big code returns if the number of words requested requires a
response block larger than 63 words. In this case, 63 words return.
An address invalid – end of section code returns when the number of
words requested extends beyond the end of this section. The data from the
specified address to the end of the section returns.
If the processor returns any other response code, no data follows.
Read I/O Word
Hex: 23
Parameters: Address of required word
Description: You must send the I/O address using the following format
(Figure A.2):
Figure A.2
I/O Address Format
0 0 0 0 0
Rack Number I/O Group
Number
a) Output Word
1 0 0 0 0
Rack Number I/O Group
Number
b) Input Word
12136