Modbus Errors

Up to twenty Modbus errors are stored in the Modbus error list (MODBUS.ERRORS). If more errors occur, the oldest error is dropped, and the new error is stored at the end of this list. MODBUS.ERRORCOUNT is the number of errors logged since the drive powered up or the log was cleared with MODBUS.CLRERRORS. All Modbus errors are stored regardless of the state of the error mode (MODBUS.ERRORMODE).

A block read/write request is always fully executed. If a register access causes an error, the error is added to the error list and processing continues with the next register.

If MODBUS.ERRORMODE is set to 1, the drive will not return an error response. Check MODBUS.ERRORS to verify that the last request was successfully completed. If it returns 0, the request was successful.

Modbus Error Parameters Description

MODBUS.ERRORCOUNT

The number of errors logged since the drive powered up or the error log was cleared with MODBUS.CLRERRORS.

MODBUS.ERRORMODE

Enables or disables error response messages:

0: Send error response messages

1: Do not send error response messages (default)

MODBUS.ERRORS

Lists up to twenty Modbus errors. Each entry contains the Modbus address and the error code of the failed Modbus request.

MODBUS.CLRERRORS

Clears all errors stored in MODBUS.ERRORS.

The WorkBench terminal displays the list of error messages:

-->MODBUS.ERRORCOUNT
2
-->MODBUS.ERRORS
(39d:21h:30m:48s) Write 40002: Modbus error code 34 (Command Error), Error 7 (Command is read-only)
(39d:21h:45m:22s) Read 45001: Modbus error code 38 (Length Invalid)
-->