I am having an issue with one of our remote servers maintaining communications with the central Pi server. Before I ask my question, I guess I should explain how our system is set up a little bit.
We have several processing plants incorporated into our Pi system now. We have remote computers in the control rooms in each of the plants that are connected to both the private network accessing the PLCs and our outside network. These plants are in 3 - 4 different states with hundreds of miles between. We have had hardly any issue with connectivity so far except for one of our plants.
The issue we're having is that we're seeing I/O Timeout values for the tags that are associated with the plant. If I login remotely to that computer using the Remote Desktop application then the values actually start reading what is in the OPC database being pulled from the specified PLC addresses. Those values stay current with no issues as long as I am logged into the machine.
There are a few users that work on the system, so the general practice is to log out of the machine when the work is complete so it will free up the computer if someone else needs access. As soon as I log out of the computer, the data stops pulling and I receive the I/O Timeout values again.
Any thoughts?