Paolo Posted March 24, 2018 Report Share Posted March 24, 2018 Hi All, I'm a new user of the Unitronics products. I've a Visio V570 with the snap in V200-E18 E2B, now on my application I'm using the two analog inputs set as 4-20mA. I'd like to know how detect a possible fail in the analog channel (for example the wire braking.....) There is some ways to do this? I think to find for example in the system bit or system word some error code or alarm bit concerning a problem in the anolg input but I did not find anything. Maybe I tried bad...... Thanks a lot for any suggestion. Cheers PB Quote Link to comment Share on other sites More sharing options...
MVP 2021 Flex727 Posted March 24, 2018 MVP 2021 Report Share Posted March 24, 2018 Fail detection is inherent to 4-20mA. When the input sensor is at minimum value, you should see 4mA. If there is a fault (broken wire, broken sensor, etc), you should see 0 mA. Your V200-18-E2B module has 10-bit resolution, so you should see a value between 204 and 1023 in the MI assigned to the analog input. In your ladder code, just look for a value that is outside of that range to trigger your fault detection action. I would give it a little margin for error (maybe 190-1030) and also include a short timer to avoid false positives. Quote Link to comment Share on other sites More sharing options...
Paolo Posted March 24, 2018 Author Report Share Posted March 24, 2018 Thanks Flex. Quote Link to comment Share on other sites More sharing options...
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