PXI-6602 Counters

[ConcreteConn]

I am using a PXI-6602 card connected to a SCB-68 break out.  I am able to generate an output from CNTR 0 and CNTR 1.  None of the other counters 2 thru 7 appear to work.  I monitor their outputs with a Oscope and I see nothing.  Do I need to enable them some how.  

[Kevin_Price]

This sounds like a side effect of the fact that the default PFI terminals for CNTR 2-7 signals are dual-purposed and can also serve as DIO terminals.

The problem sounds kinda familiar, but I can't recall specifically what needs to be done to resolve it.  Among the possibilities:

- make sure no DI or DO task is running and taking ownership of those PFI pins

- use "export signal" functions to explicitly route a counter's internal output to a PFI pin

- check the power-up state for these terminals as well as any options for tri-state

-Kevin P

[ConcreteConn]

How do I use an "Export Signal" function?

[Kevin_Price]

It'd look like this.  Just configure the export before starting the task.

-Kevin P

[ConcreteConn]

No,  I have not resolved the issue.  I suspect that it has something to do with the SCB-68 breakout that I am using.  When I use SCB-68A all of the counters work as expected.  The SCB-68 is populated with resistors.  The output pins of the counters that do not work (CNTRs 2,3,4,5,6) all appear to be connected to resistors.  The outputs when viewed on an OScope appear to be dragged down.  I am suspicious that CNTRS 2,3,4,5,6 can not be used on the SCB-68 when it is populated with resistors.  I could not find an electrical schematic to verify my suspicion.

[Kevin_Price]

I kinda remember changing the DIP switches in the SCB-68 when I was using a 6602.   The factory default was best for the more common MIO boards.

I just found this article that gives some more info, the 6602 manual may have more yet.  According to the article, the 6602 needs the DIP switches configured for direct feedthrough mode.  May as well inspect the switch config on the SCB-68A too.  Though it seems to work, it'll be best to configure it as recommended.

-Kevin P