How to generate a short pulse output with a hardware timed analog input

[LindaW]

Hi,
I have a DAQPAD 6070E (so I have to use traditional NI-DAQ). I acquire data using AI Single Scan, so that I can do a hardware timed acquisition. On the output side, I would like to generate a 4 Volt output signal, that I can drop to zero for a brief time (less than 1 microsecond), and then bring the output voltage back up to 4 Volts. I would drop the voltage once approximately every 100 msec. My analog input runs at a scan rate of 20,000 Samples/sec.

Is there a way to generate this short drop on an analog output line? Am I limited to doing an analog output at 20,000 samples/sec because of my analog input hardware timing requirements?

Any help and suggestions would be greatly appreciated.

Thanks.

[Otis]

The from looking at the Product Data Sheet for the max analog output rate on the DAQPad 6070E and I found it to be 1 MS/s, so that means you can have 1 us down and 1 us back up in theory. I checked the slew rate on that device and found that it is 20V/us, so you shouldn't have a problem with actually dropping down 4V and then back up 4V.

It should be possible to use a rate faster than 20 kHz for Analog Output, but even with that, your total pulse duration will be 2 us.

If you need something faster than that you might be able to invert some of the Generate Single Pulse VIs, which can have a resolution of 2/(Clock Rate) for your pulse. However, doing so will give you a 5V signal instead of a 4V signal.