ni usb 6255 oem differential input

[MansoorEE]

I need to use 74 channels as single ended analog inputs and the 6 as differential inputs. Can I use AI 74 to AI 79 as differential inputs?

[Izzzzz]

Hello MansoorEE,

Unfortunately you cannot set up 74 single ended and 6 differential inputs. Each differential input utilizes two channels and there are only 80 channels on the USB-6255. You can setup 68 single ended and 6 differential inputs or 74 single ended and 3 differential inputs.

Best Regards,

Izzy O.

Applications Engineer

National Instruments

ni.com/support 

[MansoorEE]

I know that. My question is that can I use two adjacent channels as differential inputs, or are there any issues with that? Because someone told me that you have to have a difference of 8 channels between each differential input. Is that true.

[Esteban.R · Accepted solution]

Hi MansoorEE

That is correct if you have a look to the NI 625x manual and specifications it says . “Refer to the M Series User Manual for more information”

When you look for the M Series User Manual in the table 3-1 page 3-2 it says

For differential measurements, AI 0 and AI 8 are the positive  and negative inputs of differential analog input channel 0.

Here is a screen shot of a section of that table.

Regards

Esteban R.

[MansoorEE]

Thank you Esteban.R