PLC5 : Connecting differential output instrument to single-ended card

Hi all,

I have a PLC5 rack that is actually full(No place for an aditionnal card). The rack has a couple of spare inputs on 1771-IFE cards and I need to hook up an instrument that requires a differential input.

Since AB documentation tells not to mix "singled-ended" and "differential" input configuration on the same card and all of them are configured as "single-ended", I was asking myself : Is there a way to connect a differential output instrument to a single-ended input using a converter or some kind of isolator ?

Thanks !

if the device supplies an isolated output you *may* be able to hook up it's common to the card common along with the other single ended commons. this may make it more susceptible to noise.

I would use an isolator. See links below for a couple vendors, there are many more.

http://www.miinet.com/products/sg_signal.shtml

http://www.automationdirect.com/adc/Shopping/Catalog/Process_Controls/Signal_Conditioners

Mickey said:

I would use an isolator. See links below for a couple vendors, there are many more.

http://www.miinet.com/products/sg_signal.shtml

http://www.automationdirect.com/adc/Shopping/Catalog/Process_Controls/Signal_Conditioners

Click to expand...

Me too. The isolator will guarantee it's safe to connect the commons together which is really what is meant by "single ended".

I was planning on using a ABB analog signal isolator.

Your answers confirmed me that it is the right way to do it.

Thanks !

johny-rock said:

I was planning on using a ABB analog signal isolator.

Your answers confirmed me that it is the right way to do it.

Thanks !

Click to expand...

Your welcome.