Rockwell Automation 1770-KF2 Data Highway or Highway Plus Interface Module User Manual - Manual (Page 194)

Error Reporting
Chapter 7
7Ć39
PLCĆ5 Diagnostic Counters
Byte No.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
29
30
31
ACK Timeouts
NAK No Memory Received
Num Claim Tokens
NAK No Memory Sent
CRC Errors
Num Duplicate Packets
Token Timeouts
Retries
Messages Sent High
Messages Sent Low
Messages Received High
Messages Received Low
Commands Gen High
Commands Gen Low
Requests Executed High
Requests Executed Low
Replies Sent High
Replies Sent Low
Rack 1 Timeouts
Rack 2 Timeouts
Rack 3 Timeouts
Rack 1 CRC Errors
Rack 2 CRC Errors
Rack 3 CRC Errors
Rack 1 BT Errors
Rack 2 BT Errors
Rack 3 BT Errors
Rack 1 Retries
Rack 3 Retries
Adapter Timeouts
Undeliverable Replies
PLCĆ2/PLC
The full-duplex protocol (and its half-duplex variation) provides for a
message packet that contains a reply to have a status byte reserved in its
header. This byte (known as the STS byte) provides information about
the execution or failure of the corresponding command that was
transmitted from the computer.
A reply that returns zeros in the STS byte means the command was
executed at the remote station. Non-zero status can be divided into two
categories: remote errors and local errors. Remote errors mean that a
command was successfully transmitted by the network controller to
another station, but the remote station was unable to execute the
command.