Appendix
A.1 Modbus TCP
90 Equipment Manual, 09/2022, L1V30415168B-03
A.1.2 Modubs exception codes
Overview
Table A- 2 Modubs exception codes
Function
• The function code in the
request is not a permissible
action for the slave.
• The slave is in a status in which
it cannot process a request of
this type. This is the case, for
example, if it has not yet been
configured and is requested to
return register values.
codes are supported.
Address
This address is not permissible for
the slave. This is the case, for
example, if the combination of start
offset and transfer length is invalid.
number of registers.
Value
The request contains a data value
that is not permissible for the slave.
This indicates an error in the
remaining structure of a complex
request, e.g. an incorrect data
offset and the specified
data length in the
command are correct.
Failure
Error in processing the data:
An indefinite error occurred when
the slave attempted to execute the
offset and the specified
data length are correct.
The action has been rejected
because the write protection is set.
Deactivate write
protection.