Rockwell Automation 1770, D17706.5.16 Ref Mnl DF1 Protocol Command - Manual (Page 143)

9–5 Diagnostic Counters
Publication 1770Ć6.5.16 - October 1996
1747ĆL541, ĆL542, and ĆL543 (SLC 5/03 and 5/04 processors)
DH485 Diagnostic Counters
This counter byte Counts the number of
0
Total message packets received, low byte
1 Total message packets received, high byte
2 Total message packets sent, low byte
3 Total message packets sent, high byte
4 Message packet retries
5 Retry limit exceeded
6 NAK, no memory sent
7 NAK, no memory received
8 Total bad message packets received
9 Bad messages due to illegal type (i.e., control byte bad)
10 Bad messages due to bad CRC
11 Bad messages due to character with parity error
12 Bad messages due to character with framing error
13 Bad messages due to overrun error
14 Number of unexpected characters received А
А If this counter is not zero, it could indicate that an internal hardware problem has occurred. This
problem could be that the communication channel's receiver has been disabled, but the DH485
driver is still receiving characters. If the controller is operating properly, this counter should remain
at zero.