I/A Series G3 Modbus - Receiving invalid transaction ID in response to Modbus TCP message request

Issue

This issue has been seen Modbus TCP between I/A Series G3 ENC and Eaton PXM meters where the PXM does not respond to the ENC within the message timeout period.  The ENC discards the request and sends a new message with a different transaction ID. The Eaton PXM meter responds using the previous transaction ID causing the ENC to discard the message and generate an error.

Product Line

TAC I/A Series

Environment

I/A Series G3, ENC-410, ENC-520

Cause

Transaction IDs become out of sequence.

Resolution

The driver now recognizes that the device is responding out of sequence and resets the session with the device.

Upgrade ModbusTCP module to revision 3.5.34.1. 

Download ModbusTcp-3.5.34.1.zip, extract, and install as required.