RBC Posted September 25, 2019 Report Share Posted September 25, 2019 Hi. Hope someone can help. I've got 2 analog input cards in my system. All configured the same. The one card my temp is stable but the 2nd card the reading fluctuates a lot. from 1 to 35 to 17 and so on. Connected pt100 connected to convertor to 4-20ma directly in panel to see is cable fault. Still the same. Any ideas please. Thanks. Quote Link to comment Share on other sites More sharing options...
bobnorway Posted September 26, 2019 Report Share Posted September 26, 2019 check your grounding, analog inputs don't tolerate much common mode offset. the fluctuating siganal could be routed near a noisy source, for example a VFD motor. temporarily switch the two and see if the problem follows the sensor. Quote Link to comment Share on other sites More sharing options...
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