miketranch

Thanks. I see now that misread the user guide where it says "Digilent has created a reference WaveForms workspace for easy visualization and measurement of main signals and quantities of the Current and Power Adapter." I thought it said MAINS signals. My mistake. That said I suggest you remove the word "main" as it really isn't needed, and might confuse others too. IMO this product would be Much more useful and interesting if it did support measuring AC line voltage. I do hope the board itself will be prominently labeled with the voltage and current limits. And IMO advertising should be very upfront that this is NOT for AC mains. I also think there should be a fuse to protect the current shunt. Just my opinions, but thanks for considering

I'm pretty sure you can create the frame in the digital pattern generator, and just trigger it. I don't think you need a script or SDK.

I got email today including link to the new AC Mains Voltage, Current, Power adaptor. So far I've bought and used every optional test fixture, and this one looks really useful too! BUT, I checked the schematic and was shocked (no pun intended) to the full AC line voltage connected directly to scope differential inputs?! How can that be? I was expecting significant attenuation and ideally a MOV or something to protect against voltage spikes. I must be missing something here, surely this has already been considered. Please help me understand. Thanks

Thanks very much. Side note, when I was at Tek, many customers wanted this feature too, and I lobbied on their behalf.

Please check again, I edited and reloaded as JPG and they show up. IMO a good heavy ground is called for here. As you know, traditional T&M is in a metal chassis and has good solid ground. I'm just trying to make my AD2 more robust. I was going to put a bananna jack there, but space was tight and I always use this ground lead so I soldered directly.

So, here I am in the T&M section of forum, and the button to make a new post says Ask Question. I have indeed asked questions and got excellent support, thanks! I just posted about adding a ground wire to BNC adaptor. Not really a question. I checked the rules and it doesn't really address this. At the top level forum the button says create new post or similar. Maybe there's a different section for T&M discussion ?

The BNC Adapter is great, but lacks a proper ground IMO. It's all too easy for a scope ground lead to come in contact with something other than ground. The BNC Adapter ground connects via USB to PC ground. If the PC ground connects to AC power safety ground, a high current can result. So I decided to add a good solid ground wire to BNC adaptor board. It connects to the scope BNC shells. I clip this to a solid ground, same one I used for the ESD protection mat. IMO, the BNC Adapter should include this from factory. Maybe in a future rev. In the meantime, this is a quick and easy fix.

Just a reminder that USB connects ground from the Discovery2 to ground of PC. Depending on your PC, that could mean the Discovery2 ground has a path to AC power/safety ground.

In Scope app, View menu, there is "Counter." What does it do? I looked in online help, it's not mentioned. Also searched this forum. Sounds like it could be useful, but doesn't seem to do anything? (Note, this screen grab is from demo mode, but it acts the same with my Discovery2, with scope running and triggered...)

I have Discovery 2 and using latest version of Waveforms. When I click Single, I would like the plots to disappear while waiting for the trigger. EDIT: I did find the Clear Buffers icon (broom) and that works, but is a couple extra clicks. Would it be possible to add a preference/setting to make it do this automatically when Single (trigger) is clicked?

I already have AD2 and am considering AD3 as well, particularly interested in FIR filters in acquisition system and local loopback to AWG. If AD2 and AD3 can be used together, reasonably seamlessly, that would seal the deal. As I understand it, Waveforms can control one Analog Discovery at a time, but multiple instances of Waveforms can be run under Windows. So multiple Analog Discoveries can be used at same time, but their data will be in separate windows. Ideally all four waveforms could be plotted, zoomed, measured, input to math waves, as one virtual 4 channel scope. Is there a way to merge the data stream from multiple waveforms instances?

Thanks again for your help. I did connect probe ground to DUT ground first, and then the probe grabber tip to what I expected to be a low level signal. I concluded that I had charged up the "ground" of the (floating) laptop and AD2, and when I connected probe ground to DUT ground, there was a discharge current. I'm familiar with ESD testing, but reasoned this scenario would be more stressful than say the Human Body Model... HOWEVER, you mentioned PIEZO transducer, and I don't know if you're PSYCHIC? but in fact I was probing across a tom-tom head on an e-Drum set! And yeah, I gave it a good hit with a drum stick. The idea was to characterize that signal before connecting it to an Arduino. (Doh, AD2 is 20x the cost of a lousy Arduino, what was I thinking?) I was using a 10x probe, but yeah maybe the signal went over 500V?! BTW I also have 100x probe, so add not-using-that to list of my mistakes! I made this a new post to alert folks that laptop ground might be floating. Maybe everyone knows that... I did receive ADG612YRUZ chips from Mouser, am now waiting for a chance to visit a friend with SMD rework station. I will update that thread on how that works out. I did also check the VREF_SC2 and VOFF_SC2 and they check out OK. Buffers and DAC are OK cuz I can still see normal (except for DC offset) waveforms. Thanks again for great support!

Just a quick note, based on real world experience. If running AD2 via USB power from laptop, and laptop running on batteries, then AD2 "ground" is floating, not connected to earth ground. And depending on the laptop and its power supply, even when plugged into AC line, the ground might still be floating. So, if you have some ESD ('static electricity') charge on yourself, and you handle the AD2, you might charge up that floating ground, so the AD2 and the laptop have some potential charge built up. Then when you connect o'scope probe to a circuit that is grounded, the discharge current might damage the scope inputs. In my case it damaged the first chips in the signal path, ADG612YRUZ. FYI, you can get them from Mouser, Digikey etc., but they are tiny TSSOP package, so replacing them is not trivial. Lesson learned: always make sure all grounds are really grounded before connecting AD2 to the circuit under test. And obviously, I should have been wearing an ESD wrist strap. Hope this helps folks avoid my mistake.

FWIW, I've had my AD2 for 3 yrs now, well acquainted with it, and I'm a retired FAE from the T&M industry. Yesterday I think I zapped my DA2. It was running on battery laptop power, so floating ground. I used a 10x probe to something, that was grounded, and I think there was an ESD discharge when I connected the probe ground clip. Scope Channel 1 shows a 14.1 volt offset error and Channel 2 shows -0.7 volt offset error. The digitizers still work, still show waveforms. I tried the calibration wizard and it throws an error on the first step, with all scope inputs grounded, 0V was expected, 2.74V was measured. I looked at the reference manual and I suspect one or more chips in the input stage are damaged. Is there any repair service available? I'm not properly equipped to repair SMD. It would be great if there was a module level exchange.