ANDing ORing counter arm start triggers

[MrSethT]

I am using a 6602 PCI to collect an array of time stamps of pulses using DAQmx.dll i.e. .NET. c#.  In order to synchronize the 2 encoder tasks data for comparison, I create a "starter" task that is triggered by a digital edge trigger (a PFI).  Then I create a task for each encoder and make their  digital edge triggers point to the output of the "start" task.  

This is all working very well, but I have been asked to make a modification so that instead of a single PFI being used as my digital edge trigger, a combination of PFIs can be used (AND/OR).  From my research so far, I think this can be done with a digital pattern trigger, but since I am collecting counters, I am using an ArmStartTrigger and ArmStartTrigger does not have a digital pattern trigger, only StartTrigger does.  Sooo, my question is how do I do it?  My guess is that I can replicate what ArmStartTrigger does using only the StartTrigger, but I do now know how.  I am also open to AND/ORing the ArmStartTrigger, but I haven't seen where that's possible. 

Thanks so much for your time.

[Kevin_Price · Accepted solution]

The 6602 won't support a "digital pattern" trigger.  Not many devices do, as far as I know.

Only an Arm Start trigger can be used for counter input tasks, not a regular Start trigger.

The AND / OR'ing would need to be done with an actual logic circuit.  Unless you have another DAQ board around that supports digital change detection.  (M-series and X-series MIO boards support it as do some dedicated DIO boards.)

-Kevin P