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About Funkhauser

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  1. 1794-OA16 Modules, Outputs passing voltage

    Hmm very good replies thank you. I wasn't aware of leakage current, or most likely forgot from my semester of studying solid state switches, which does explain reading a voltage. I'm surprised AB tech support didn't bring this up while speaking with them today! Most of these outputs are firing solenoids but we had wiring issues regarding the field neutral so no proper drain path. As for the outputs which turned themselves on, they were not random so they must be caused by a separate problem. I was reading a voltage (drain current) on what appeared to be random points but is most likely due to the multimeter measuring 100 vac at 2.5 mA. When I turned off the outputs the light indicators turned off so I'll have to recheck my logic to see if anything is writing to the output word. Very happy my own ignorance may be the culprit rather than a corrupt PLC file or an evil bus bug that corrupts anything hooked up to it. Thanks very much for the replies.
  2. Hello, I have a very strange issue with a rack of remote IO on my Ethernet setup. There is one rack which contains 3 1794-OA16 (120 VAC output) modules connected to 1794-AENT module. I have several other IO racks on this network without any issue. The issue is that I'm measuring 100-115 VAC on random outputs (they change after cycling power or replacing parts). I also will see output lights on for a couple of these points which also can be seen in the output word while online with the compactlogix PLC (1 on the output point while monitoring the word). These outputs are untouched in the PLC program, verified through cross checking in RSLogix 5000. Also, unplugging the Ethernet cord and separating the TB3 bases so each output module is isolated I still see voltage on the outputs. I have also replaced the AENT, TB3, and OA16 devices and still have this issue. I isolated the modules from the field wiring and 100% certain there is no wiring issue causing this. I'm wondering if this is a case of a corrupt PLC file screwing up the configuration sent to this specific AENT? Has anyone encountered this problem before? Not all outputs have this voltage so I'm led to believe this is not normal situation of seeing voltage but no current. I appreciate any feedback, thank you. EDIT: Realized title error, please excuse it. EDIT 2: Spoke to AB tech support, they said it is a possible bus issue but I'm not convinced since all the parts have been replaced.