Simple DAQ to generate 2 external triggers

[jason1313]

Hi!

Please excuse my naïveté, I am new to all this!

I'm looking for the simplest DAQ to generate two external TTL triggers for two cameras, at different frequencies (10 Hz and 200 Hz).

Initially I was looking at the USB-600x line as their docs mention hardware-timed Analog Output channels.

But it seems that for this application it is generally recommended to use more expensive DAQs like the USB-6210 which support counters/timers for pulse generation. Is this necessary or can I just use the hardware-timed Analog Output channels in the simpler models?

Thanks so much!

[Kevin_Price]

It might work to use AO, but it's less than certain.  The voltage levels should be fine, the problem is the rise time and fall time of transitions.

AO will have a limited "slew rate" for changing voltage from 0->5 or 5->0 volts.  The corresponding rise and fall times will be much longer than that of a true TTL logic circuit.

It'll depend on how sensitive the camera trigger inputs are to such things.  Some logic circuits can be pretty sensitive to slow rise and fall times and produce erratic results during the transition time.  Others handle it fine.

All that said, you could add Schmitt triggers inline between your AO and cameras to be *certain* to deliver proper signals to the cameras.

-Kevin P