Replacing software trigger with physical trigger

Hi,

I am new with control system so excuse me if this sound trivial.

Currently I am using a USB6001 running a Labview program with 4 radio buttons trigger 4 different set of codes for Analog Output to a servo motor.

I like to replace the 4 radio buttons with physical push bottoms or equivalent, and change the radio buttons to indicators.

I was reading the manual about PFI and the USB6001 only has two of them.  Does that mean I am maxed out with the ability to use 2 physical triggers? 

Can I use the digital Input for the same purposes?

And if there are other way to achieve this, please let me know. 

Thanks, Billy