AD2 Pattern Generator timing issue

[KLPE]

Hi, I'm using the pattern generator to create a digital signal on my AD2 unit. I see that sometimes the 1st low pulse on my arbitrary signal is 567,68 us wide, other times its 293,29 us wide. I'm looking at the signal with the AD2 scope function. (100 us/div).

The frequency of the digital signal on the pattern generator is 105567 Hz, and the samples: 1Ki 

I'm not changing anything in the setup, just pressing the run button on the pattern generator multiple times and observe the timing on the scope. But I can't believe that the pulse width should be able to change that much.

On the attached image the two different pulse widths is seen in the persistence screen.

I'm running WF ver. 3.18.1 / Patterns setup = 16 x 1k under device manager

 

Any Ideas why I have this tolerance on the pattern generator?

/Klaus

 

[attila]

Hi @KLPE

Probably you are seeing your first short pulse and the other two (or likely just the second) longer pulse.

[KLPE]

Hi Attila,

If you look at the "pattern generator" time scale on the ima n see the total signal is close to 10 ms. The scope/Persistence time scale is 900us. You are looking at the first pulse in the signal and it is not having the same low time every time I run the pattern generator. I have also attached two more scope screenshots of the two different low time periods I see when I run the pattern generator. Something strange is going on...

[KLPE]

I just hooked up my "large" oscilloscope and watch the signal generated by the AD2 pattern generator on this. The signal from the pattern generator is OK. As Attila mentioned earlier, the problem is that the AD2 oscilloscope miss the first pulse and instead triggering on the second pulse sometimes. The large oscilloscope capture the signal correct every time with the same channel & trigger settings as the AD2.

/Klaus

[attila]

Hi @KLPE

You could also use the AD2 Scope for wired capture if you zoom out, increase the time base.