Accessing timer/counter functions on USB-6001

[drbh]

I am working with a USB-6001 and trying to use the timer/counter functions to generate a frequency output signal for a stepper motor drive.

It appears that the PFI channels (P2.0 and P1.1) can be adapted to counter/timer functions. However, none of the example VIs recognize either PFI0 or PFI1 or P2.0 or P1.1 as counter/timer.

How do I configure the USB-6001 to access this functionality? How do I specify these ports in a VI?

[drbh]

I should add that /ctr0 is not recognized either.

[Kevin_Price]

Pulse train generation is not supported by the (very limited) counter on the USB-6001.  It can only do edge counting.

If you intend to do any kind of velocity ramping, you should probably consider a device that can perform buffered pulse train generation, such as X-series.  Or else a dedicated stepper controller (complete with its own trajectory generator) you can talk to over a communication connection.

-Kevin P

[drbh]

Thanks. Still, how do I access the (even limited) counter/timer functionality of the 6001? How are the PFI ports configured/specified for use in a VI?

[Kevin_Price]

PFI terminals are an *external* interface to the DAQ device's *internal* I/O resources for digital and timing signals.

A digital I/O task is configured with a syntax similar to "Dev1/port0/line0".  A device's manual will identify how the individual digital lines map to specific PFI terminals..

A counter I/O task is configured with a syntax similar to "Dev1/ctr0".  There is a default mapping between a particular counter's internal I/O pins and the external PFI terminals.  Many devices are very flexible about allowing you to specify non-default PFI terminals to be mapped instead.

One can usually use the same PFI pin simultaneously for multiple *input* tasks.  But not output tasks, for fairly obvious reasons.

-Kevin P