Operating instructions

Diagnostics and Troubleshooting PTQ-MCM ♦ Quantum / Unity Platform
Modbus Communication Module
ProSoft Technology, Inc. Page 95 of 139
April 29, 2008
7.3 Error Status Table
The program maintains an error/status table that is transferred to the processor
in each read block. You can use the error/status data to determine the "health" of
the module. The data block structure is describe in the Status Data Definition
section. The errors generated by the module are displayed in the following
tables.
7.3.1 Standard Modbus Protocol Errors
Code Description
1 Illegal Function
2 Illegal Data Address
3 Illegal Data Value
4 Failure in Associated Device
5 Acknowledge
6 Busy, Rejected Message
7.3.2 Module Communication Error Codes
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
7.3.3 Command List Entry Errors
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 Invalid swap code