Communication Sequence - Siemens SINAMICS Series Operating Instructions Manual

10.8.6

Communication sequence

Logical error
If the device detects a logical error within a request, it responds to the controller with an
"exception response". In the response, the device sets the highest bit in the function code
to 1. If the device receives, for example, an unsupported function code from the controller,
the device responds with an "exception response" with code 01 (illegal function code).
Table 10- 64 Overview of exception codes
Exception
code
01
02
03
04
Process data monitoring time (setpoint timeout)
The "Setpoint timeout" only applies for access to process data (40100 ... 40109, 40110 ...
40119). The "Setpoint timeout" is not generated for parameter data (40300 ... 40522).
Fieldbus interface:
In parameter p2040 you define the time for cyclic data exchange for process data.
Setting range 0 - 2000 s.
The time depends on the amount of data to be transferred and the control.
"Setpoint timeout" (F01910) is issued by the Modbus if p2040 is set to a value > 0 ms and no
process data is requested within this time period.
COMM BOARD:
In parameter p8840 you define the time for cyclic process data exchange.
Setting range 0 - 2000 s.
The time depends on the amount of data to be transferred and the control.
"Setpoint timeout" (F08501) is issued by the Modbus if p8840 is set to a value > 0 ms and no
process data is requested within this time period.
SINAMICS DCM DC Converter
Operating Instructions, 12/2018, A5E34763375A
Modbus name
Illegal function code
Illegal Data Address
Illegal data value
Server failure
10.8 Communication via Modbus TCP
Remark
An unknown (unsupported) function code was sent to the
device.
An invalid address was requested.
An invalid data value was detected.
The device has terminated during processing.
Descriptions of functions
549