what is need of 4 to 20miliampear & 0 to 20miliampear

so many controllers output is of 4 to 20 ma whearas some of them has 0 to 20 ma output why Posted in: #Coffee Room

the digital signals work on standard 0-5v , so having a 4-20ma and a 250 ohm resistance we can output a 0-5v range from the controllers.
But if 0-20ma is used, where 0ma for minimum value and if there is a failure in the transmitter wire,say it is grounded then the value read is 0ma again, so to identify this failure Industries now mostly stick to 4-20ma .

ajay mogle

so many controllers output is of 4 to 20 ma whearas some of them has 0 to 20 ma output why

Can you please let me know where you read this ? I mean in datasheet or anywhere else? As I know this 0 might be referred to Input only pin of Controller.

visit https://www.control.com/thread/1026235722
You will get a better insight.