We have a NovaTech OrionLX polling a Metz Connect MR-DIO4/2 RTU at several locations using the Digi TransPort WR31 as a “go-between.” The RTU utilizes RS-485 communications. A few months back, we had programmed the Digi for RS-485 communication in order to talk to this RTU, but we could never get the two to communicate. On this forum, I came across an individual who was having the same exact problem – and his resolution was to program the Digi for RS-232 communication and then add an RS-232-to-RS-485 converter in between the Digi and the RTU. Once we followed that advice and implemented his strategy, everything took off and started working just fine.
I don’t know if that configuration is related or not, but now we are seeing the communications failing intermittently between the OrionLX and the Digi. We are able to connect straight to the Digi just fine each time there’s a failure, and when we send a command to reboot the Digi, communications with the OrionLX are fully functional once again. These intermittent failures can be quite scattered. Sometimes, the communications go for a few weeks without failure. And when the failure eventually does occur, sometimes communications are automatically re-established within 2-3 hours. Other times, communications are not re-established and we’re forced to go the route of sending a reboot command to the Digi to start things up again.
Any idea what could be causing this and what preventive measures we could possibly take to try to eliminate these kinds of intermittent failures?