Triggering a DIO line based on AI value.

[Labtek]

I am using Labview 7 with an E-series DAQ card. The system is reading a waveform from a function generator. It needs to trigger a DIO line (set it high for few seconds) when the value at Analog input is at certain value (e.g @ peak or zero crossing set by a control on front panel) It's going to be one shot operation. I was wondering if it can be accomplisghed without adding any external hardware/circuit to E-series DAQ card.

Thanks

[BJD1613]

You shouldn't have any problem doing this. This is done in the LV Daq and Signal Conditioning course through NI. If you get a chance I would suggest taking it. If you are familiar with LV 7 and the daq assistant you can develop an analog triggering to be dependent on a level and then you will have to develop another task for you digital operation. There are also alot of good examples in LV that should help you with this. Hope this helps.

[Labtek]

I am aware of these features in the LV but my concern is how deterministic this approach would be if I let LV control turning the DIO on instead of a built in feature of NIDAQ. In other words can I tie the triggering on Analog Input to actuate the DIO deterministically.

Thanks

[BJD1613]

This is a good example of software triggering. THis is almost everything you want. Cont Acq&Chart Samples-Int Clk-Analog Start.vi

for a more deterministic approach you can use hardware triggering. If you have a counter available you will have the ability to use hardware triggering. What kind of determinism are you looking for??

[Labtek]

Thanks.I'll check the example out. I would like to get a response within 50 msec deterministically. Sounds like a small number but with windows who knows..!

So how would I use hardware triggering using counters?

[Labtek]

Sorry, I meant 5ms or better.

[BJD1613]

check out some of the examples that specify hardware triggering. Basically it is monitoring a pin on the counter out put that you will trigger using the gate. If you are familiar with counters you can trigger an output using the gate input. Hope this helps.