Siemens S7-1200 System Manual page 735

Variable
RCV_TIMEOUT
Connected
Table 12- 53 MB_CLIENT protocol errors
STATUS Response code to
(W#16#) Modbus client
(B#16#)
8381 01
8382 03
8383 02
8384 03
8385 03
Table 12- 54 MB_CLIENT execution condition codes
STATUS MB_CLIENT parameter errors
(W#16#)
7001 MB_CLIENT is waiting for a Modbus server response to a connect or disconnect request, on the assigned
TCP port. This is only reported 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 reported 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 did not respond 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 reported after any configured retries (if applicable) have been attempted.
8188 Invalid mode value
8189 Invalid data address value
818A Invalid data length value
818B Invalid pointer to the DATA_PTR area. This can be the combination of MB_DATA_ADDRESS +
MB_DATA_LEN.
818C Pointer to a optimized DATA_PTR area (must be a standard DB area or M memory area)
8200 The port is busy processing an existing Modbus request.
8380 Received Modbus frame is malformed or too few bytes have been received.
S7-1200 Programmable controller
System Manual, 03/2014, A5E02486680-AG
Data type Default description
Real 2.0 Time in seconds that the MB_CLIENT waits for a server to respond to a
request.
Bool 0 Indicates whether the connection to the assigned server is connected
or disconnected: 1=connected, 0=disconnected
Modbus protocol errors
Function code not supported
Data length error
Data address error or access outside the bounds of the MB_HOLD_REG address area
Data value error
Data diagnostic code value not supported (function code 08)
Communication processor and Modbus TCP
1
12.5 Modbus communication
735