The current setup:
Head-end: iFix 5.8 communicating through OPC/IGS server.
Remote: TransPort WR21 Cellular > Micrologix 1400 Ethernet.
WR21 has a static IP address from ATT. Connection is LTE, there do not appear to be any issues with signal strength/quality as the installation is a fairly urban area.
The WR21 is configured with a port forward to the Micrologix e-net port.
Communications seem to work fine when initially powered up, but eventually completely fail after a few hours. I have extended poll times to 5 minutes in iFix and expanded comm timeouts to max in both the OPC server and PLC interface.
I can always reach the digi interface, there doesn't seem to be a problem there - it seems as though the ethernet port on the micrologix shuts down.
Anybody had any luck with Micrologix Enet processors (particularly the 1400) over cellular?