PFI

[the_intern]

What is the difference between PFI and TTL digital signals? What is the main purpose of using PFI lines ?

[Nick_CH]

Hello,

Your question is answered on the following KB: PFI Lines (E series VS. M Series).
To resume, For M-Serie, Each PFI can be individually configured as the following:
- Static Digital Input
- Static Digital Output
- Timing Input Signal for AI, AO, DI, DO, or counter/timer functions
- Timing Output Signal from AI, AO, DI, DO, or counter/timer functions

The Static TTL Digital I/O  provide only an input or an output with the on/off ability.

Best regards
Nick_CH

[the_intern]

So, I guess I will be using NI PCI-6289 rather than NI PCI-6541. I have 8 signals that needs to be DI/DO PFI lines. How should I connect those lines, just straight each line to PFI0 through PFI7 and that's it? What other lines should be connected in order to PFI lines to work?

What if I want to use timer/counter on some of them? Is there a certain line that should is related to the timer/counter line and be connected somewhere?

Thanks

[Elizabeth W]

Hello,

The pinouts for your device (found either in your manual or by right-click on your device in Measurement & Automation Explorer) show you which physical pins on the device correspond to the the PFI lines. 

There are certain PFI lines that correspond to the different counter terminals.  For example, on the PCI-6289, ctr0 source corresponds to pin 37, which is PFI 8.  Let me know if you have any questions about how to look up all of the pinouts.