single and differential output sensors.

I recently picked up for evaluation an analag input module made by ICP-DAS, this unit has 8, 14 bit analog input channels. 2 of which are single ended input, and the other 6 are differential input.

My question to all of the minds here is, can I convert single ended output pressure transmitters (4-20Ma, 2 wire) to differential output so that they may be recognized by the analog module.

I understand that the difference between single and differential is that the signal floats and is not referenced to a common ground as in single output. Is there an easy way to simulate a differential output?

Any help would be appreciated.

Thanks
Willpower

At my plant we have the same model transmitter (loop powered) used in single ended, and differential schemes. The only difference is the wiring. The main difference is the 24Com wiring. I assume the card you are evaluating has a typical wiring diagram. It should show the difference.

I don't know what make/model of transmitter you're using, but I've never encountered a loop powerd transmitter that could not be used either way.

Give me a few more details, and I'll work with you.

Ken

What model do you have, the ones I am familiar with have jumper select to make it 8 differential or 6 differential and 2 single ended.

Ken, thanks for the reply, the sensors I am using are from MSI, the data sheet is at
http://rocky.digikey.com/WebLib/Measurement Specialties Inc/Web Data/MSP-300 Series.pdf

They are 0-5000psig, 4-20Ma output, 10-30Vdc supply, 2 wire transmitter. The manual shows the red wire to the supply, the black wire to the measuring circuit with a common ground. I am using a 125ohm resistor as specified in the analog module manual.


I dont know if I am missing something, it should be pretty simple.

Willpower

Guest, the model I am using is i-7017 from ICP-CON. You are correct, this unit is also jumper select for 8 diff or 6 diff and 2 single ended inputs.

Willpower

I believe the sensor you are using is loop powered, and can be used as either differential or single ended. Your input card should have a wiring diagram for a loop powered differentail input. Just follow that.


Ken

I figured it out myself, it wasn't my sensors or my hookup, but none of the differential channels were enabled. I talked to tech support after I found this out and they said they should have been enabled at the factory. Guess somebody screwed up.

Willpower100