Sigma IC-Modbus system alarm messages


Default system message No. 19997 Contact Sigma Support is shown in the Sigma Alarm Manager

Product Line

Satchwell Sigma


Sigma 4.00



Sigma System messages are held in a master file, in early versions of Sigma this file could be edited to include messages for new integrations or new error messages. From Sigma 4.0 and later system messages are now hard coded into the system and can no longer be edited.

If an undefined system message is received it is likely that a later version of controller firmware is installed in the field and the Sigma software does not contain the newer system message.


If an unknown error message is received, the Sigma software should firstly be upgraded to the latest version. To assist in tracing the source of errors related to IC-Modbus (system messages 19992 - 20002) the exception code from the modbus device describes the failure mode, in Sigma the reason is calculated as follows:

System Message Number = 19992 + exception code seen in Modbus message -1


19992 = Illegal function code

19993 = Illegal data address

19994 = Illegal data value

19995 = Slave device failure

19996 = Acknowledge delayed

19997 = Slave device busy

19998 = ??? (undefined error code )

19999 = Memory parity error

20000 = ??? (undefined error code)

20001 = Gateway path unavailable

20002 = Gateway target device failed to respond.