Analog Inputs alarm on V750 V200-E18......

[Paolo]

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

 

[Flex727]

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.

[Paolo]

Thanks Flex.