Dave Posted December 9, 2012 Report Share Posted December 9, 2012 Hi. I have a V570-57-T20B with V200-18-E1B, EX-A2X, EXL-CAB2000, IO-D16A3-TO16, IO-D16A3-RO16 & IO-DI16. System has been installed and running for approx. 6 months. ( Actually, two identical systems, with a third just being installed now). Yesterday, I was onsite to make some program modifications. I had connected to PLC but not made any changes. Everything was fine, until, right before my eyes the PLC stopped, screen went black with "expansion io error". LED's on EX-A2X indicated that power and comm were ok. The io modules connected to the EX-A2X had flashing run indicators and all I/O indicators were off. I used the visilogic to RESET the PLC and all seemed fine again, except the I/O modules still had flashing RUN LED's and were not functioning. I unplugged the cable from PLC to adapter....no change. The power and comm LED's were both still on. The PLC showed no errors and appeared to be running. Powered off a couple times to reboot....nothing changed. Did a "Initialize and reset" from visilogic....nothing changed. Eventually I swapped the adpter module with another one and everything was back to normal. I will return the EX-A2X for warranty replacement. My main concern, however, is the fact that the I/O module could be defective or even just unplugged and the PLC did not indicate any error. This could cause catastrophic machine failure should the PLC continue to run without a portion of the I/O functioning. Any ideas what can I do to make sure the the adapter is connected and functioning? I suppose I could pulse an output from the snap-in I/O to an input from one of the remote I/O and monitor that input. I am hoping for something that doesn't require additional wiring. Appreciate any thoughts on this. Dave Quote Link to comment Share on other sites More sharing options...
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