Application summary:
Detect and read a voltage on an analog input and create a trigger signal
when this voltage goes below/above a defined value. Then after some
(adjustable) time I want a digital output to toggle (and stay there
until next trig event + delay). Critical time issue is the time from trigger
event to toggle occurs on the digital output -thus I want to do it in HW
(on DAQ board and avoid SW timing issues).
--> I am considering to use Ai to trig the counter that toggles an output
pin after X ticks (20MHz to 100kHz clock) -every time the voltage drops below a threshold value.
I want to use the M series 6281 DAQ board.
It seems that it is possible to have a counter to toggle an output:
http://digital.ni.com/public.nsf/allkb/F9C5AE8585D1353586256AC100820B5D
BUT, in the M.Explorer there is no choice to make the any counter output "toggle",
only:
- 1 pulse
- N pulses
- Continues pulses
- Continues pulses (HW timed updates)
-> I am missing the option "Toggle output" here...
So the only way I can set this up is like in this example with the property node thing:
http://zone.ni.com/devzone/cda/tut/p/id/5387
I have searched the web for examples and better description of the
counters than chapter 7 in the User Manual of 6281 does, but I have not been able to find any. However, I think I can use the example above with some exeptions. Can anyone help me out with that to get it according to my description?
- set up AI to generate a trigger pulse on a specific voltage value
- set up the correct properties for the counter (in ex above)
- select from different clock inputs (20MHz to 100kHz) to counter.
Thanks,
Olav Gundersen
