Keysight DSOX1102G triggering of WaveGen - Page 1
Forum section: electronics / testgear

author: qpit3a
author_rank: Contributor
timestamp: January 25, 2018, 11:22:41 pm
content: I am considering this scope and have almost decided to get it, but I saw Dave's bode plot trick (yes I know the scope has that function built in - but it seems limited), I was wondering if it's possible to trigger on the start of the FM modulation of the internal modulation. I noted a menu from a mikeseletricstuff review of the scope where it shows that the trigger source can be wavegen or wavegen mod see attached screen grab. The manual I found online doesn't seem to show all the trigger options..Mikeselectric stuff:https://youtu.be/dm9sGL9Rmv4. Dave's bode plot trick:https://youtu.be/uMH2hGvqhlE

author: Someone
author_rank: Super Contributor
timestamp: January 25, 2018, 11:47:27 pm
content: Wavegen Mod as a trigger source does exactly what you are thinking, keeps the modulation waveform static on the display. There is enough memory to keep the sampling rate up for audio range sweeping, but it would get a little narrow for RF. Also of note is that the function generator is not synced on the modulation so if you turn on averaging while triggering from the modulation waveform it averages the trace to zero(ish).

author: bicycleguy
author_rank: Frequent Contributor
timestamp: January 28, 2018, 07:07:27 pm
content: I played around with this a while ago on a DSO-2014A. I made these notes at the time:Code:This is for sweeping from 0 to 20kz out of wave gen, triggering out of back into channel 4.The device under test input from wave gen, output to channel 1.Wave gen is set at 10khz sine, fm modulation with 1hz and 10khz dev.ANALOGCh 1 Scale 640mV/, Pos 2.51200V, Coup DC, BW Limit Off, Inv Off, Imp 1M OhmProbe 10.000000 : 1, Skew 0.0sCh 4 Scale 2.00V/, Pos 2.57500V, Coup DC, BW Limit Off, Inv Off, Imp 1M OhmProbe 1.0000000 : 1, Skew 0.0sTRIGGERSweep Mode Normal, Coup DC, Noise Rej Off, HF Rej Off, Holdoff 40.0nsMode Pulse Width, Source Ch 4, Polarity Negative, Qualifier t > 20.000000ms, Level 1.27500VHORIZONTALMode Normal, Ref Left, Main Scale 50.00ms/, Main Delay 50.000000000msZoom Scale 10.00us/, Zoom Delay 490.400000000msACQUISITIONMode Normal, Realtime On, Vectors On, Persistence OffMEASUREMENTSFrequency(1), Cur 19.81kHz, Mean 19.97kHz, Min 19.69kHz, Max 20.25kHz, Std Dev 120Hz, Count 54Frequency(4), Cur 19.94kHz, Mean 20.02kHz, Min 19.57kHz, Max 20.45kHz, Std Dev 230Hz, Count 54I think these notes were from early on in my play and other ways to trigger and definitely higher frequencies were possible.The capture shows the frequency sweep zoomed at the top and the bottom showing the trigger into channel 4 and the low frequency at the start of the seep. I think this worked better than setting the internal trigger in the menu for some reason I don't remember. This was also before I did the hack for more memory which helped.

author: qpit3a
author_rank: Contributor
timestamp: February 05, 2018, 11:36:05 am
content: Thanks, I have ordered the scope from Measurement Innovation, free shipping, cheaper price (slightly) and the good thing about ordering from WA is that I can talk to them after I get home from work. Except they have none in stock.. Still very friendly and they rang me to let me know. Good service so far.