Analog Edge triggered Pulse Output - retriggerable for different AI edges?

[RVallieu]

I am wondering if this is even possible to accomplish in HW.

We have not acquired the HW at this point - so I figured this a two part question

a) is this possible

b) what X-series PCIe card would support it (or if none what would?  R-series I know would work, but I'd like a DAQmx supported solution FIRST)

What I need to do is monitor an analog input channel from 0-10V.  That is scaled to a force level.  I want to take readings at an even interval, i.e. acquire every volt starting at 2 Volts and stopping at 8 volts.  To take these readings the instrument we are using has a Trigger Input that will force an acquisition.

I want to know if I can reset the Analog Edge trigger level of a CTR Pulse output task on any of the X-Series boards, or if I would have to restart the task with a new Analog Edge level after it had triggered the first time.  I don't expect the load ramp to be very fast, so this may be an option for me.

[Mcdan]

Ryan,

First off, analog triggers are not supported for counter tasks on X Series... This should technically be possible in hardware, but we don't have software support for it.  If this is a feature you would like to see added, please submit this idea to the Data Acquisition Idea Exchange.

That being said, it is certainly possible to use an analog trigger to generate a digital pulse.  To do this you have several options.  In all cases you will need to set up an analog input, analog output, digital input or digital output task, and configure this task to use an analog trigger.  One simple option would be to use an analog triggered digital output task, and use digital ouput to generate a pulse of whatever spec your instrument needs (port 0 on X Series devices do have a dedicated timing engine, so it should be fairly easy to generate a short pulse).  Additionally, once any task has configured an analog trigger there is a terminal which represents the output of the analog comparitor used by the analog trigger on the device (/DevX/AnalogComparisonEvent) which is routable.  This can be routed directly to a PFI line, or can be used as a digital start trigger for a counter generation task.

That covers the signal routing you'll need to do.  Unfortunately for your use case, the analog trigger cannot be re-configured while an analog triggered task is running.  This means that to change the voltage level, you will need to stop and restart your task.

Hope that helps,

Dan