What is the correct wiring of 9 Pressure Transmitter (2 wire type, 4-20mA output) on NI USB-6211?

[vinigodoy]

Details:

NI USB-6211 Analog Input Config. (p. 60/204 of the PDF)

Pressure transmitter connection diagram* (the 4-20mA diagram on p. 2/2 of the PDF)

*Translated to English = Pin 1 (supply source), Pin 2 (signal) and Pin 3 (OFF)

Hi!

Since I want to connect 9 sensors on a device that has only 8 differential-type inputs, I must wire them on RSE or NRSE mode.

First, I'll have to find out what 'AI Ground Reference Setting' my Signal Source has. How can I do that? As my power supply unit has only V+ and V- on its output, i guess it's floating, therefore my Signal Source is also floating, right?

Assuming it, I made two different connection diagrams of my setup, one for NRSE and one for RSE, both of them attached here. Are they correct? Which one is better, NRSE or RSE?

Thanks!

[FloresFe · Accepted solution]

Hey vinigodoy,

To check if your V- is common to the Ground, you can measure continuity between the V- and the Chassis (considering that it is gounded) or to the building GND. In case you test it and notice that it is not connected to the GND, then it is floating and you should connect as your diagram shows for RSE.

If it is grounded, you should proceed to use the NRSE configuration.

I hope that helps.

Best,

[vinigodoy]

Hi FloresFe!

I've tested it and the supply source is indeed floating.

Then I connected based on my diagram for RSE config. (the one attached) and it's working!

Thank you!