Host Engineering Forum

General Category => Do-more CPUs and Do-more Designer Software => Topic started by: PLCwannabe on February 11, 2020, 12:21:42 PM

Title: Analog Channel Failure
Post by: PLCwannabe on February 11, 2020, 12:21:42 PM
I'm trying to set up BRX for 4-20 milliamp sensor. As soon as i set the configuration to 4-20ma, I get a channel failure alarm. (see attached) when I set it to any other configuration( 0-10v, 0-5v) the warning disappears. I did hook up a 4-20 ma sensor to see if warning will disappear, the channel doesn't work, warning is still there. What could be the problem?
Title: Re: Analog Channel Failure
Post by: BobO on February 11, 2020, 12:23:15 PM
I would stick a VOM in the circuit and see how much current it flowing through it.
Title: Re: Analog Channel Failure
Post by: ADC Product Engineer on February 12, 2020, 07:56:10 AM
If the channel is configured for 4-20ma, it must have a 4-20ma device wired to it or it will give an error.   That's just how 4-20ma works.  If it isn't in range, it is considered to be failed.
Title: Re: Analog Channel Failure
Post by: PLCwannabe on February 12, 2020, 09:13:41 AM
Ok you guys were right. The sensor is actually a 3-wire type. I've only used  2-wire sensors before. I just assumed that the channel failure without a sensor hooked up meant a module problem.