Problem with pin reference (USB 6218)

[User_1979]

Hi evryone,

I am confused concerning the pin references for USB-6218. MAX says to use  pin 15 and 16  for a differential AI (AI0/AIground) on the first channel. This seems correct because my measure looks ok. But when I look at the data sheet (http://www.ni.com/pdf/manuals/372085b.pdf)  these pins correspond to PFI 6/P1.2 and D ground.  The AOs don't match either.

I must be making a mistake when reading the data sheet. Would anybody know what I am doing wrong?

Thanks,

User 

[JÞB]

You have miss interperated what "Differential" means

Max is telling you to use AI0+(P15) and AI8+(P16) to create a task that reads the voltage differeance between those two nodes (A differential measurement)

A non referanced single ended measurement (NRSE or Pseudo differential) would use AI0(p15) and AISN(p23)

A Referanced Single Ended (RSE) would use AI0(p15 and AIGND(p28)

PFI 6/P1.2 and D ground are on pins 8 and 5.  

[User_1979]

Hi,

Thanks for your answer. I am sorry but I still don't understand how to read correctly the data sheet.

For instance, how do you get  to your conclusion "PFI 6/P1.2 and D ground are on pins 8 and 5" using the datat sheet I have send? Don't they correspond to pin 15 and 16 according to data sheet?

User

[User_1979]

I have just realised I hadn't attached the correct data sheet (the one I wanted to disccuss I mean) in my first email.

All my questions and comments relate to his one http://www.ni.com/pdf/manuals/372083c.pdf       (page 6)

[Remi.D]

Hi User_1979,

Did you use a simulate device in MAX?

These Connections refers to this datasheet of the USB 6218 (P.15). Your measurement seems ok between pin 15-16 (AI0-8), the behaviour is normal.

Also you can find the device pinout within MAX by right click on the device and click to view the pinout.

Regards,

[Dennis_Knutson · Accepted solution]

You say you are using the USB 6218 but then you post the manual for the USB 6218 OEM. Which are you actually using?

[User_1979]

Hi Remi and Dennis,

You were right Dennis, I hadn't noticed this data sheet was for the OEM version.... When looking at the correct one I get the same information as what I get with MAX and what I have seen with my measures.

Thanks a lot,

Regards,

User