miv2k

I think the WFG preview is shifted down on the attached screenshot, is it not? It should oscillate around +3V with 10mV amplitude, but instead it appears to be centered around +3V-5mV?

But should this new option not be in the tab where the green triangle with “Wavegen 1” currently is or be triggered by the “Stop all instruments” square button in the top right corner?

Yeah, schematic looks so much better now. Thanks!

Hi, A couple of times I ran into situations when after stopping all instruments including WFGs to rearrange connections, I still found WFGs outputting steady DC voltage. That's partly expected, since there is an "Idle: Offset/Initial" combo box, at least for variable form signals, but when it comes to generating DC, it becomes really confusing and somewhat dangerous. In DC mode there is only one control "Offset". So when configuring a WFG to run in DC mode, I'd naturally set this Offset to the desired value. And then would expect that switching WFG between Stopped and Running should trigger the output voltage between open circuit and this value, but no! Regardless of whether WFG is shown as Running or not, DC is applied. I understand that there is a separate Enable checkbox in the WFG configuration window, and it's that checkbox that can be used to disconnect WFG's outputs, but it's present only in the WFG window. The green/red indicators in the tabs and the big red "Stop all instruments" button have no effect on WFG's output in DC mode, it continues to run. Do you think it may be possible to transition WFG's outputs to open circuit when the WFG is Stopped? Thanks!

Btw, the connection schematic in the top right corner is very difficult to read with this palette. Would it benefit to store it as a bitmap and then display it using text color?

And "File -> New Tracer -> Empty" or "File -> New Tracer -> Clone" do nothing. Should they open new tabs?

Not sure, if it's due to an implementation difficulty, an overlook or a checkbox that I didn't find, but saved references of trace plots lack labels. In the attached screenshot it's Vrc.

Got it now, thanks. So, ADC conversion frequency is way higher than the sampling frequency, for each sample AD2 manages to do a ton of conversions, which it normally averages (hence the smooth plot), but also shows min/max values in the form of this noise band to give an idea of what extremes the ADC saw while digitizing.

Thanks for the explanation. Is this the actual noise that the AD2 is observing, or some calculated one based on theoretical resolution? What I'm getting at is that the bands look really wide, and the signal on the other hand is very clean, look at the zoom for instance. With noise that big should I not see a lot of jagged lines in the capture?

Hi, What do the two wide bands around the scoped graphs represent (in the left window)? Thanks!

Well, the ringing as a concept is no secret, but what's causing it here? Inductance in breadboard? Too fast a transition? For the heck of it I removed crocodile ground wire from the probe and added a thing like below, but it didn't change the situation much.

IDK. What could be the reason? Initially I thought that ringing could be because I just hacked it on a breadboard with long leads on the feedback resistor, but now I fed the generated signal to another trigger in the same chip and scoped right from the second trigger's output pin. I still see ringing. Higher frequency too now. Probably because I'm not loading feedback with the probe's capacitance anymore.

Oh yeah! Tried 74HC14N to generate a square wave, and at 6MHz with 10x probe it looks way more square than the one from WG. Even some ringing. Good to know the limits.

Thanks for taking your time to answer my questions. I don't have another waveform gen capable of 5-30MHz, but I'll see if I can come up with 5-10MHz square wave and check if it looks better on AD2 scope than the one in the first screenshot. If it does, then yeah, it will confirm that I'm hitting AD2's WG limits here, not the scope.

Oh, you mean you skipped probes altogether and just used a BNC to BNC cable... Here's my capture with 1x probe going to WG1 0R, and I think it matches your green plot. Should I blame then the oscilloscope probes that came with AD2 for the reduced frequency range? I then fail to understand marketing material... "When used with BNC probes the adapter increases the oscilloscope bandwidth from 9MHz to 30MHz". Even if we say that the bandwidth is given by -3dB cut-off (which for measuring equipment is kinda extreme), you and I are seeing only 8MHz with the BNC probes, far cry from 30MHz.

Thanks for a quick response. I'm trying to understand the legend in your screenshot. How was the orange plot obtained? I had a 1x probe connected to CH1 in DC coupling mode going straight to BNC of WG1 with 50R jumper.

Hi, I've been playing with Analog Discovery 2 (totally new to it, so please forgive me if I ask stupid questions) and noticed that when a 5MHz square wave from WG1 was scoped by a 1x BNC probe on CH1, it looked like a triangular wave. That was somewhat unexpected to me, since the specs call for 30+MHz bandwidth @ -3dB. I then dug out an AD2 Reference Manual, and on page 30 of it saw how they demoed AWG spectral characteristics by running Network Analyzer in WaveForms by feeding WG1 directly to CH1, and their plot was also suggesting -0.5dB @ 5MHz and -3dB @ 20MHz. I did the same, and got way different results: -0.5dB @ 2MHz and -3dB @ 5.5MHz for 1x probe and even more bizarre plot for 10x. Why are my results so much worse than the specs? What may I be doing wrong here? All screenshots are attached. Thanks! This is how how a 5MHz square wave looks when scoped by enclosed BNC 1x probe: This is characteristic measured by 1x BNC probe: This is characteristic measured by 10x BNC probe: This is what AD2 reference manual calls for when BNC probes are used ("Figure 21 shows the typical spectral characteristic of the AWG. In the first experiment (solid line), a coax cable and a Digilent Discovery BNC adapter were used to connect the AWG signal to the Scope inputs")

Hi, Are triggers supposed to work in Discovery2 Demo mode? I somehow just can't configure even the simplest case of a Rising Edge. Have Wavegen1 emitting 5V 1MHz square wave for 10us every 500us, configured Scope 1 in Repeated mode, Normal trigger, Source=Channel 1, Condition=Rising, Type=Edge, Level=2V, and while I can see the signal with large time base, when I zoom in, it just slides off. Moving trigger level doesn't help, switching Scope Source to Wavegen C1 doesn't change anything... I'm most puzzled of what I'm doing wrong, and am thinking that perhaps triggers are not supported in Demo mode? It's a WaveForms 3.18.1 running on Linux. Help and thanks!