Reply To: Porcheson plc

Jones124000John C Jones
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If you have a safety relay monitoring this door (which you should have with a forced guided relay) and you are operating at 24VDC,  use a good multimeter (Fluke 87) and check for a voltage drop to the PLC input. The meter can be set up to record minimum and maximum values. If there is no voltage drop, replace input module. Most 24VDC input modules have a threshold of 18VDC to turn on or off. If there is a voltage drop after 2 secs, (below 18VDC) for an instance, check your DC Power supply with a scope for line noise or other equipment interfering.