OkiePC
Lifetime Supporting Member
I have a PLC5 with SLC IO. A couple of times per day the SLC scanner faults: "ESO","L03". The book says IO parity error (slot 3). We replaced the scanner, IO cards, backplane, power supply, and changed power sources. The power looks clean on a scope. We even ran our "blue hose" comm. cabling across the factory floor for awhile. Then, for no apparent reason, the problem went away for about four months; then it suddenly reappeared. The card in slot 3 is an OW16 (relay card). We added surge suppression to all the outputs on this card. I'm going to add another card to an empty slot and begin moving outputs to it one at a time. If I can't fix it, I'm going to add a PLC operated relay to the system to cycle power to this rack automatically when the rack fault occurs! Is it possible for a field device connected to this card to be causing our problem?