jfrye
Member
We are having an issue with a SLC5/05 timing out reading from the IOs on the backplane. Very briefly the setup is, 1747-L551 (SLC5/05), with 1746-IA16, -OW16, -NI4 (x2), and -NO41, with a PVP1000 as an HMI. Issue started a month or so ago with the original PLC, "Timeout reading N15:0 from SLC... Timeout reading from O0:0 from SLC... Timeout reading from T4:10-T4:11 from SLC... list goes on." We replaced the PLC, first time different rev/series number, and bad data tables, ended up PLC ran for maybe a day and then was completely incommunicable; tried battery reset, etc. nothing, but whatever. We replaced with another PLC with rev/ser no. closer to the existing, installed, programmed, and has been working well for close to a month now. Until last night, we received the same timeout alerts. In the past a reboot would reset the condition and the machine would run for 1-2hrs, I am assuming that holds true today but I have not verified yet this morning.
We added a PID block to control the speed of a pump several months ago but I would have thought if that were an issue it would have cropped up sooner, as we had a math error due to an infinite loop from the PID that we resolved with a reset block, can provide specifics if needed but don't recall offhand. That was in Feb 2018. Timeout issue started in early-mid May '18.
Any help would be appreciated, thanks!
Jeremy
We added a PID block to control the speed of a pump several months ago but I would have thought if that were an issue it would have cropped up sooner, as we had a math error due to an infinite loop from the PID that we resolved with a reset block, can provide specifics if needed but don't recall offhand. That was in Feb 2018. Timeout issue started in early-mid May '18.
Any help would be appreciated, thanks!
Jeremy