Rockwell Automation 2755-DM9, -DM9E High Speed Decoder - Manual (Page 128)

Chapter 8
Host Commands Using the RS-485 Interface
8–16
DATA (Bytes 4 through X) - Depending upon the function code, the
following data is returned:
Read Diagnostic Counters Reply
Read Diagnostic Counters - The reply returns values for twelve diagnostic
counters:
1) Total Message Packets Received (2 bytes).
2) Total Message Packets Sent (2 bytes).
3) Message ACK Time-out/Retries (1 byte).
4) Message Retry Failures (1 byte).
5) Messages Replied with NAK-NOMEMORY (1 byte).
6) Message Received with NAK-NOMEMORY (1 byte).
7) Bad Messages Received (1 byte).
8) Messages Replied with NAK-NOSERVICE (1 byte).
9) Message Replied with NAK-SOLICIT (1 byte)
10) Messages Replied with NAK-TOOBIG (1 byte).
11) Messages Replied with INVALID CMD (1byte).
12) Messages Received with INVALID ADDR (1 byte).
The data in the read diagnostic counters reply message has the following
structure:
READ DIAGNOSTIC COUNTERS REPLY
00000000 01000110
TRANSACTION WORD
HI Byte LOW Byte
COUNTERS
(In sequence listed on previous page)