How to use analog Triggering and External clock scan

[wyuan]

Hi, there. I want to measure the engine cylinder pressure with an PXI6070-E card and BEI encoder. I have tried using Cont Acq&Graph ExtScanClk D-Trig.vi and Cont Acq&Graph ExtScanClk Soft A-Trig.vi , but they don't work. What I did was to connect a 50HZ pulse to PFI0 (analog triggering, I changed the code from digital triggering to analog triggering), and a 100K pulse to PFI7 (startscan), and an 50 HZ analog signal to ACH0. But the code always says: timeout. If I use internal clock, it works fine. Could you please give me some help? THANKS A LOT!

[JoshuaP]

Hey Wyuan,

I tested the Cont Acq&Graph ExtScanClk Soft A-Trig.vi and it worked fine. However, the Cont Acq&Graph ExtScanClk D-Trig.vi has a small error in its logic that will prevent the data from ever being displayed to the graph. In order to run the examples you need to connect a trigger to pin 11 and a scan clock to pin 38. A 10kHz square wave would be fine for the clock signal and just a single pulse would work for the digital trigger.

One additional think to keep in mind is the grounding. You might need to connect you ground from your signals to a DGND pin. I am including the two programs that I used for the test.

I hope this helps,

Joshua

[wyuan]

Hey, JoshuaP,

Thanks. I will try your examples. The Cont Acq&Graph ExtScanClk D-Trig.vi only works for digital triggering, doesn't it? That means I cannot connect an analog signal to pin 11, right? Can I just change the triggering from digtal-A (2) to analog (1) for analog triggering?

Thanks a lot for your help. I will let you know my results.