Siemens SIMATIC S7-1200 - Page 1178

Communication processor and Modbus TCP
13.5 Modbus communication
S7-1200 Programmable controller
1178 System Manual, V4.2, 09/2016, A5E02486680-AK
Table 13- 60 MB_CLIENT protocol errors
STATUS
(W#16#)
Response code to Modbus
client (B#16#)
Modbus protocol errors
8381
01
Function code not supported
8382 03 Data length error
8383 02 Data address error or access outside the bounds of the MB_HOLD_REG
address area
8384 03 Data value error
8385
03
Data diagnostic code not supported (function code 08)
Table 13- 61 MB_CLIENT execution condition codes
1
STATUS
(W#16#)
MB_CLIENT parameter errors
7001 MB_CLIENT is wait
ing for a Modbus server response to a connect or disconnect request, on the assigned
TCP port. This code is only returned for the first execution of a connect or disconnect operation.
7002 MB_CLIENT is waiting for a Modbus server response to a connect or disconnect request, for the assigned
TCP port. This will be returned for any subsequent executions, while waiting for completion of a connect
or disconnect operation.
7003
A disconnect operation has successfully completed (Only valid for one PLC scan).
80C8 The server has not responded in the assigned time. MB_CLIENT must receive a response using the
transaction ID that was originally transmitted within the assigned time or this error is returned. Check the
connection to the Modbus server device.
This error is only returned after retries (if applicable) have been attempted.
8188
Invalid mode
8189
Invalid data address
818A
Invalid data length
818B Invalid pointer to the DATA_PTR area. This can be the combination of MB_DATA_ADDRESS +
MB_DATA_LEN.
818C Pointer DATA_PTR points to an non-optimized DB area (must be a non-optimized DB area or M memory
area)
8200 The port is busy processing an existing Modbus request.
8380
Received Modbus frame is incorrect or too few bytes have been received.
8387 The a
ssigned Connection ID parameter is different from the ID used for previous requests. There can only
be a single Connection ID used within each MB_CLIENT instance DB.
This code is also returned as an internal error if the Modbus TCP protocol ID received from a server is not
0.
8388 A Modbus server returned a quantity of data that is different than what was requested. This code applies
to Modbus functions 15 or 16 only.
1
In addition to the MB_CLIENT errors listed above, errors can be returned from the underlying T block communication
instructions (TCON, TDISCON, TSEND, and TRCV).