end/stop trigger signal express

[Ben-]

Using Signal Express, I am trying to set up a hardware end or stop trigger for acquiring data.  I see that there are stop condtions available on the analog input lines, but I would like to be able to use those for acquiring data and have the trigger (a positive swinging TTL pulse) set the end trigger.  I do not see an option for using the digital inputs to set an stop trigger (only a start trigger) in Signal Express, and the searches I have done have only shown results (albeit workarounds really) for LabView.

I would like to know if it is possible to set a stop trigger using Signal Express using the digital inputs.

The NI board is PCI-6122

Thanks.

[Aaron O]

Ben,

The closest you are going to be able to get to what you want is to use a DAQmx acquire with a Start Trigger and a Reference Trigger. When the Start Trigger pulses, the acquisition will start sampling. When the Reference Trigger pulses, you will get a pre-defined number of samples before the Reference Trigger as well as additional samples after. You will have to set Acquisition Mode to N Samples to do this. This is the closest to a start and "stop" trigger you can get in SignalExpress.

The other option is to use Start and Stop Conditions in the Recording Options of the acquisition. This can record data based on hardware, software, or date/time conditions. This will be you're best bet for creating a log of data during particular events.

Regards,

Aaron