We have project where we are using the PCI-MIO-16E-4 card to acquire analog data (1 channel) in the double buffered mode (We are using Visual Basic.)
Now, I would like to use the analog trigger to determine when this data drops below a certain level, and to send out a real time TTL signal to indicate this event--without interrupting the collection of data.
I have explored the Configure_HW_Analog_Trigger and Select_Signal functions, but can not seem to find a way of routing the output of the analog trigger to any of the I/O lines.
I have also explored several work-arounds using an analog output channel to send out a TTL compatible signal, but have not found a way to do that without interrupting data collection.
Is there a way to do what I want to do, or can you suggest a work around?
The analog hardware trigger is an internal trigger signal and cannot be directly routed to the I/O connector. Instead you could use it to trigger a pulse generation on one of the counters on the board. What you need to do is to configure the counter for retriggerable pulse generation and use the GPCTR_Change_Parameter function to select the gate. See the Ni-daq Function Reference Manual for the legal parameter values. LabVIEW users will find a similar example program at http://zone.ni.com/libraries/ Search for +"analog trigger" +counter