6602 Synchronize ALL 8 outputs without external signal?

[Jed_Davidow]

Howdee all..

I have an application that's actually pretty simple.  I need to generate pulse trains on all 8 counters of a 6602, and they need to be triggered together via a software trigger (Frequency will be the same, but their delay/Phase and DC may be different channel to channel).

What's the best way to do this?

• Can I set them all up under the same task and then call "Start"?
• What about using the output of one counter to trigger the others?  That output MUST be available as an output signal though.  But I can set things up so that it's initial swing is used to start the task.
• Does it make sense to physically connect PFI0 to PFI1 and then trigger them off PFI1 using PFI0 as the signal?

Just a reminder, I am using all 8 counters as output.

[Jed_Davidow]

OK.  So I guess I posted too late in the day and no one chimed in- so I broke out the hardware, wired up some LEDs and here we are...

Looks like you can create one task, add each of the counters to it and then start the task.  At least, this SEEMS to work with two channels.  I will have to break out a DAQ card or a scope (which I don't have) to verify that they are synched.

BUT if this is the case, why are there so many examples of starting two counters on a 660x card with AI Start signals and the like?

[Marcus_M]

Hi Jed,

This is Marcus in Application Engineering.  It looks as though you are on your way right now in regards to getting your program set up.  To help answer some of your question yes, as you have seen multiple counters can be placed in one task.  You could wire the output of one PFI line into a second one and use the output of the first PFI line both as a source to separate device as well as using it as a trigger for a second PFI line that will trigger your reaming counters.  

Are the examples that you are referring to located in LabVIEW?  I am looking for the specific examples you are referencing.

Regards, 

Marcus 

[Jed_Davidow]

Hi Marcus,

Right now the code I wrote looks like this (all counters are on the same 6602 card..)...

This appears to work, but I can't be sure that the counters all started together without a scope.  So the $64K question is, since they are all on the same card, does the code above start all the pulse trains instantaneously, or will I have to go back and set them up to use a digital trigger (and do that thing with the PFI lines)?

As for the other example...

https://decibel.ni.com/content/docs/DOC-11755

[Marcus_M]

Hi Jed,

Would it be possible for you to post a larger picture of your code or the code itself so that I can take a closer look at it and determine if it will work for your application?  

Thanks,

Marcus