Search the Community
Showing results for tags '20256'.
Hello, I am having an issue with intermittant connection to a remote PLC. The setup is as follows: Server has a VPN connection to a GSM router on site. This is connected via ethernet to the PLC. What I have found: I lose the ability to do a socket ping to the PLC on 20256. When I lose this ability, I also lose the ability to pull telemetry data off the PLC from the registers. (makes sense, they use the same port). I am doing this ping test from the local router on site, over the VPN. The issue is therefore not with the VPN itself, but the connection between the router and the PLC. The ladder logic code that manages the connection is attached. Can you see where I have gone wrong? How can I increase the robustness? Additionally, can you suggest timeout/keepalive settings that would help? At the moment, I can regain the connection by restarting the router (set to a automatic timed restart at the moment). Additionally, I have noticed more than once that if I go into the socket parameter screen on the PLC, it has sprung back into life. (maybe coincidence?) Many thanks in advance for any help!
Hello, I have a project that has reliability issues that seem to stem from the PLC losing connection to its router on socket 20256. On a PLC where the connection is lost: If I ask the router to do a standard ping against the router, it succeeds. If I ask the router to do a TCP socket ping with 20256, it fails. (on a PLC I am successfully getting data from, this succeeds) The kludgy way I am temporarily getting round this, is the router is set to do a hard reset every 4 hours which reinitialises everything Bit of background: Remote server using unicomdriv.dll is communicating via VPN over a GSM modem to the PLC over Ethernet (sounds dodgier than it actually is!). I have a screenshot of the bits of code that manage the connection on the PLC code, what I am thinking is I need something to detect a situation of the PLC losing connection or no successful data transfer over socket 1, and initiate a sequence to regain the connection. Any suggestions? Any suggestions of parameter settings for timeout and keepalive ect... on the PLC itself? Roy