adccommunitymod (AutomationDirect) asked a question.
Analog signal conditioner
Created Date: September 11,2007
Created By: Bob S BN
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I have just purchased four industrial flow meters with 4-20 ma. analog outputs and need to connect to a f2-04ad-1. The meters state that each loop be isolated from the other. The AD input modules all appear to have common grounding so I can't connect directly. Does anyone know of a signal conditioner module anywhere that can accept all four inputs isolated and transmit to the plc, or am I destined to buy and wire four individual conditioners at $89 a piece?? Thanks for your help, Bob
Created Date: September 11,2007
Created by: AZRoger
Bob,
I'm not an electrical engineer, but this seems like an impossible condition to meet, even with signal conditioners. Eventually every current goes to ground or V+. Does each sensor require it's own, ungrounded power supply? Sounds wierd.
Roger
Created Date: September 11,2007
Created by: larawaym
Bob,
I highly doubt you'll have any problem with them. I use a variety of flow meters, pressure transmitters, gas analyzers, and several products using the shared common and have never had any issue. I would imagine by saying that all loops must be isolated they just mean the signal wires.
Don't take my word as fact, but I think you'll be just fine.
Mike
Created Date: September 11,2007
Created by: Bob S BN
Thanks for your thoughts.
I just talked to the factory that built the meters. Turns out they have doing testing with this same plc and module. He says they have problems related to the ground loops.
He said 4 seperate loop powered conditioners will solve the problem, like the fc-11. Or, cheaper than that, he said it has also worked well to use a seperate power supply for each meter and another one powering the module.
Thanks again for your help, Bob
Created Date: September 11,2007
Created by: Bob S BN
I have just purchased four industrial flow meters with 4-20 ma. analog outputs and need to connect to a f2-04ad-1.
The meters state that each loop be isolated from the other. The AD input modules all appear to have common grounding so I can't connect directly.
Does anyone know of a signal conditioner module anywhere that can accept all four inputs isolated and transmit to the plc, or am I destined to buy and wire four individual conditioners at $89 a piece??
Thanks for your help, Bob