Siemens SIMATIC S7 System Manual page 488

Libraries
9.3 Modbus RTU library
MBUS_MSG
error code
0
1
2
3
4
5
6
7
8
11
12
101
102
103
104
105
106
107
108
488
Description
No error
Parity error in response: This is only possible if even or odd parity is used. The
transmission was disturbed and possibly incorrect data was received. This error is
usually caused by an electrical problem such as incorrect wiring or electrical noise
affecting the communication.
Not used
Receive timeout: There was no response from the slave within the Timeout time.
Some possible causes are bad electrical connections to the slave device, master and
slave are set to a different baud rate / parity setting, and incorrect slave address.
Error in request parameter: One or more of the input parameters (Slave, RW, Addr,
or Count) is set to an illegal value. Check the documentation for allowed values for
the input parameters.
Modbus master not enabled: Call MBUS_CTRL on every scan prior to calling
MBUS_MSG.
Modbus is busy with another request: Only one MBUS_MSG instruction can be ac-
tive at a time.
Error in response: The response received does not correspond to the request. This
indicates some problem in the slave device or that the wrong slave device answered
the request.
CRC error in response: The transmission was disturbed and possibly incorrect data
was received. This error is usually caused by an electrical problem such as incorrect
wiring or electrical noise affecting the communication.
Invalid port number
Signal board port 1 missing or not configured
Slave does not support the requested function at this address: See the required
Modbus slave function support table in the "Using the Modbus master Instructions"
help topic.
Slave does not support the data address: The requested address range of Addr plus
Count is outside the allowed address range of the slave.
Slave does not support the data type: The Addr type is not supported by the slave
device.
Slave device failure
Slave accepted the message but the response is delayed: This is an error for
MBUS_MSG and the user program should resend the request at a later time.
Slave is busy and rejected the message: You can try the same request again to get a
response.
Slave rejected the message for an unknown reason.
Slave memory parity error: There is an error in the slave device.
System Manual, V2.3, 07/2017, A5E03822230-AF
S7-200 SMART