jcraft
Member
We have a small Mitsubishi plc that controls a shrinkwrap machine. Called to service it yesterday and found a bad 24vdc power supply in it that was basically cycling on and off. It would come on for about 1 second then immediately shutdown, therefore it was powering the plc up and down constantly. It did it probably 50 times while I was there and who knows how many times prior to that. We changed the supply and everything powered up and the plc is in run mode. However,parts of the machine are working others are not. Some I/O is turning on and off. At this point we don't have any schematics for the machine nor do we have the original plc program or the software to link up. Anyways, I am assuming that continuous power up and down of the plc could likely cause something to become corrupt within the program as i don't think the plc even reached its run state before losing power again. Let me know your thoughts on that. Thanks