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3 MODBUS STANDARD FUNCTION DETAILS
3.9 Get Communications Event Counter (FC: 0BH)
3.9 Get Communications Event Counter (FC: 0BH)
Operation description
Acquires the number of messages whose requested actions (read/write, diagnostics, etc.) have been normally completed.
Whether the action corresponding to the request message is normally completed or not can be checked.
Request message format (from master to slave)
Response message format (from slave to master)
■ When completed successfully
Since C24 does not support any program commands, 0000H is stored in the program command status.
Returns the count value of the buffer memory listed below to the master.
• 'Communications event count' (Un\G32523 to Un\G32587)
The count is stopped if it has reached FFFFH.
Reset the counter by any of the following methods when restarting the count.
• Restart communications option (Page 23 Restart communications option (sub-function code: 01H))
• Clear counters and diagnostic register (Page 27 Clear counters and diagnostic register (sub-function code: 0AH))
• Turn the power OFF and ON, or reset the programmable controller CPU.
■ When completed with an error
(H) (L) (H) (L)
0BH
(0000H)
Program command status
Data
Communications
event count value
Function code
(0000H to FFFFH)
8BH
Data
Exception code
Function code
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