NI9208 Wiring Question for multiple non-loop powered inputs

[breynolds]

Hey Guys/Gals,

I am in the middle of wiring up a project at work with a cDAQ, and I had a question about wiring the NI9208 module.  I have a bunch of 4 wire (non-loop powered) 4-20mA output devices that I am trying to read.  Rather than having a mess of wires pigtailed together to go into one of the 4 COM channels, and to satisify my OCD about the wires looking nice, I was wondering if it was possible to make a jumper wire from one of the Vsup terminals to one of the COM terminals and use the Vsup terminals as additional COM terminals? 

I will only be using this 9208 for 4 wire devices, so I dont need to run an external power supply to it and the Vsup pins wont be used otherwise.

I wanted to see if anyone had done this before I try it and burn something out. 

Thanks,
Bellamy

[Maxwell_Taylor]

Hi breynolds, 

This is not the intended use of the NI9208.  Having said that, after looking at the user manual, it seems like you should be okay connecting your COM terminal to the Vsup terminal in order to have more COM ports available.  You will have to do this at your own discretion because it's not supported by National Instruments.  

I would suggest branching out wires from the COM ports and connecing them to your devices.  I know that you said that you don't want to have wires everywhere but that may be your best solution.