Pulse train output simultaneous with analog I/O

[rmonti]

I need to produce a TTL pulse at 20 to 200 Hz, while simultaneously performing an analog I/O. I am currently using one of the two AO channels on a PCI-MIO-16E-4 board to generate the pulse, but I would like to free it up. The counter/timer circuits would be ideally suited to the task, but I need to provide a discontinuous pulse train (i.e. 100Hz for 100 ms, nothing for 500 ms, 100 Hz...). With the AO, this is simply a matter of generating the appropriate array. Is it possible with counters, and can it be synced to the AI/O? I have been using LabView for ~2 years, but have never used the counters. Thanks.

[June]

rmonti:
Yes, you can use counters to finite generate pulse trains. In fact, there is an example that ships with LabVIEW that demonstrates this: /LabVIEW/Examples/Daq/Counters/stc.llb/finite pulse train.vi
To do this, you will need both counters on the 16E-4 device. The vi info of the example will explain more on this.
As far as the synchronization, the counter can input an external source as its reference (into its source input), you should be able to route the update clock of the AO to the source of the counter, since two are sharing clocks, they are sychronoized.

June