Rockwell Automation 1770-KF2 Data Highway or Highway Plus Interface Module User Manual - Manual (Page 185)

Error Reporting
Chapter 7
7Ć30
31. Number of ENQs sent.
32. Number of messages that could not be successfully sent.
33. Number of reply messages that could not be forwarded and which
were destroyed.
34. 16-bit count of messages received.
35. Not used.
36. 16-bit count of ACKs sent.
37. Not used.
38. Number of NAKs sent.
39. Number of ENQs received.
40. Number of retransmissions received and ACKed. A retransmission
is a message that has a transparent word, command, and source that
match the previous message.
41. Number of STX (full-duplex mode) or SOH (half-duplex mode)
received. This is in effect a count of the number of messages that
were started.
42. Number of messages, characters, or message fragments that were
ignored.
43. Number of messages that were aborted by receipt of a DLE ENQ.
44. Number of messages that were aborted by the receipt of an
unexpected control code other than DLE ENQ.
45. Number of times the DLE ACK response was sent but there was no
buffer space for the next message.
46. Number of times DLE NAK was sent because there was no buffer.