Rockwell Automation 1770-KF2 Data Highway or Highway Plus Interface Module User Manual User Manual

Page 194

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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.

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