cRIO 9064 FPGA 9402 Trigger input on DIO not read

[Michael.Proctor]

Hi,

I have a cRIO 9064 using the C-Module 9402 as a fast DIO in a SCTL. I use it in a digital delay pulse generator (DDPG).

I have succesfully implmented the DDPG, triggered with an internal generated square wave clocked at 1 MHz.

and I measure perfect output pulses on an oscillascope.

My implementation is basically a clone of: http://www.ni.com/example/31131/en/

However when I try to trigger from an external 1 MHz, 6 volts amplitude; duty_cycle 50%, square wave coming in on the DIO3

there is no triggering, as seen on the Ticks_Between_Trig - which should be about 40, when there is correct triggering.

I have use the method  'Check Status'  to make sure the 9402 is ready before running in the SCTL.

( Note:  while it is labled Mod3 in teh screen shot, it is actaully Mod1 and it simple a namign mismatch - which when fixed does not change anything. )

I do not see any digital HIGH when monitoring the trigger input, which I do when using the internal trigger.

The LED flashes, often enough even though in reality at 1MHz.

My question is what trick do I need to have the 9402 DIO read the input signal.

I have followed the instructions here:

http://zone.ni.com/reference/en-XX/help/370984R-01/criodevicehelp/crio-9402/

but perhaps i missed something.

thanks

Michael

[Michael.Proctor · Accepted solution]

Solved,

I had a bad input pulse generator that was flacky.

When I check the pulse amplitudes on an oscilascope but then day later when I fixed my code to include the C-Module ready method,

the pulse amplitude was nolonger working, but I was still trying to test with it,

Finally I rechecked on the oscillascope again the trigger signal to find it not suffecient.

Old eqiupment getting warm.... then not working.

Michael