Help about analog trig 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!

[CoastalMaineBird]

What I did was to connect a 50HZ pulse to PFI0 (analog triggering, I changed the code from digital triggering to analog triggering),

For encoder-based (synchronous) measurements, you want to connect the once-per-rev signal (encoder index) to the EXT TRIG input (I forget the PFI numbers), and the N-per-rev signal to the EXT. CLOCK input. Use the EXTERNAL DIGITAL + triggering option, and the EXTERNAL SCAN CLOCK option. Set the NUMBER OF SAMPLES TO ACQUIRE to match your encoder resolution and off you go.

The ANALOG trigger option scans the first ANALOG channel you specify, looking for a transition across the threshold you specify. It does NOT look at the DIGITAL signal in an analog way.