ProSoft Technology MVI94-MCM-MHI - Manual (Page 62)

Diagnostics and Troubleshooting MVI94-MCM ♦ Flex I/O Platform
User Manual Serial Communications Modbus Communication Module
Page 62 of 109 ProSoft Technology, Inc.
March 29, 2011
Modbus Error Codes
These error codes are returned to the module from Modbus slave devices
attached to the master port. These codes are the standard Modbus errors. The
error codes are listed in the following table.
Code Description
1 Illegal Function
2 Illegal Data Address
3 Illegal Data Value
4 Failure in Associated Device
5 Acknowledge
6 Busy, Rejected Message
Module Error Codes
Module error codes are generated by the module’s program. These errors can
result due to configuration or communication problems. These errors are stored
in the Modbus master, command list error table. A word is allocated for each
command in the memory area.
Code Description
-1 CTS modem control line not set before transmit
-2 Timeout while transmitting message
-11 Timeout waiting for response after request
253 Incorrect slave address in response
254 Incorrect function code in response
255 Invalid CRC/LRC value in response
The following table lists the errors returned by the module for errors found when
parsing the command list.
Code Description
-41 Invalid enable code
-42 Internal address > maximum address
-43 Invalid node address (<0 or > 255)
-44 Count parameter set to 0
-45 Invalid function code
-46 All parameters set to 0
-47 All parameters set to -1
Use the error codes returned for each command in the list to determine the
success or failure of the command. If the command fails, use the error code to
determine the cause of failure.