END OF MODBUS 485 COMMUNICAITONS PROTOCOL
Function Command
(without CRC)
Action
Notes
0
11 08 00 00
Echo Message
Return the Exact Sames Message
1
11 08 00 01
Restart Communication
Restarts from a Previous 4 Command
2
11 08 00 02
Return Error Byte
Returns Same as Holding Register 23
4
11 08 00 04
Listen Only Mode
Stops the Analyzer from Responding to
Anything
10
11 08 00 0A
Clear All Diagnostic Counters
Clear Each of the Diagnostic Counters to
Zero
11
11 08 00 0B
Total Message Count
Total Number of Messages Seen by the
Analyzer
12
11 08 00 0C
CRC Error Count
Number of CRC Errors Seen by the Ana-
lyzer
13
11 08 00 0D
Exception Count
Number of Invalid Modbus Commands
14
11 08 00 0E
Number of Slave Messages
Number of Messages the Analyzer has
Returned
15
11 08 00 0F
Number of No Responses
Number of Messages Addressed to the
Analyzer that It did not Respond to
16
11 08 00 10
Number of NAK Responses
Number of Messages with Incorrect
Parameters (such as Invalid Registers or
Out-of-bounds Values) Seen by the
Analyzer
Table III: Diagnostic Functions
The diagnostic functions 0, 1, 2, 4, 10, 11, 12, 13, 14, 15, and 16 are supported.
Note that each counter will count up to 65535 but will not go any higher. They can be reset
to zero with the 10 command.
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