Post AwHuHAA0a2TONijvLE by azonenberg@ioc.exchange
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 (DIR) Post #AwHuGzXi3ZtbS2kCG0 by azonenberg@ioc.exchange
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       Will do a more proper demo of this later on, with a cleaner bench (right now I just want to update some screenshots for the ngscopeclient website).But I'm throwing together a quick demo of multiple-scope sync operation using ngscopeclient and the trigger crossbar.
       
 (DIR) Post #AwHuH079vmFhDzKVVo by azonenberg@ioc.exchange
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       For starters, the initial bench setup. This is why I'm not shooting the actual demo yet!Two scopes, one on each rack. Both happen to be Teledyne LeCroy but it doesn't matter, any supported instruments will work.Trigger in and out of each are hooked to the trigger crossbar, and ext ref input of each are connected to 10 MHz from the SRS FS752 GPSDO.CH3 of the SDA816Zi-A and CH2 of the WR8404M-MS are connected through a broadband splitter to TX0+ of the crossbar's built in BERT.
       
 (DIR) Post #AwHuH4EkbUhY0gucts by azonenberg@ioc.exchange
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       Trigger crossbar configuration: trigger out of the SDA goes to trigger in of the WaveRunner, and the BERT is producing a 1.25 Gbps PRBS-31 on TX0.You could easily replace this setup by just wiring trig out to trig in (but in my case that would mean crawling behind the bench and running cables in awkward places), and using a free-standing BERT. The crossbar just integrates the cable patching and PRBS generation into a convenient 1U package.
       
 (DIR) Post #AwHuH5lOvaPekFCDQm by azonenberg@ioc.exchange
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       Connecting ngscopeclient to both scopes, nothing is synchronized and the scopes are configured to trigger independently of one another.Nothing exciting yet, this is what you'd expect from two independent scopes that happen to be looking at the same signal.Having them in a single GUI is already convenient, though.
       
 (DIR) Post #AwHuH7J7BiyVX5yecS by azonenberg@ioc.exchange
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       Dragging the WR8 under the SDA to form a 2-instrument trigger group, they now properly trigger in lock step with the WR8 triggering when the SDA triggers.But there's still a huge offset, probably a microsecond or more, between the two because of the cross-trigger setup.So the waveforms don't line up.
       
 (DIR) Post #AwHuH8kRpaQu09lzrU by azonenberg@ioc.exchange
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       So the next step is to correct this by clicking the "deskew" button.
       
 (DIR) Post #AwHuHAA0a2TONijvLE by azonenberg@ioc.exchange
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       The wizard walks you through all of the cabling, reference clock connections, etc.
       
 (DIR) Post #AwHuHBR3q7hwKtj3Ym by azonenberg@ioc.exchange
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       The wizard then takes ten waveforms on each scope and finds the phase alignment with the best cross-correlation (doing a GPU-acclelerated brute force to find the best alignment).If all of the correlations give values within +/- 1 sample, you know you have a good calibration.If you get wildly divergent values, something is wrong with your setup.(I actually had this at first, then discovered that the WR8 had the external trigger threshold set to 0V, so it was reading noise instead of the 0-1.8V trigger pulse I was feeding it. Once I fixed the trigger threshold I got a much better sync.)Eventually I should add a pass/fail result and maybe a pretty histogram or something here.
       
 (DIR) Post #AwHuHCuWM4rouYW67M by azonenberg@ioc.exchange
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       Oops, I didn't have the WaveRunner at max sample rate (40 Gsps interleaved). Re-ran the calibration and got a slightly different result at the higher sample rate.Anyway, now that we have the calibration done, we can then hook the scopes up to real signals.Let's make things fun: we'll use the same BERT as the test signal, but connect the + differential output to the SDA and the - output to the WR8.And bump the data rate up a bit higher. 1.25 Gbps is too slow ;)
       
 (DIR) Post #AwHuHEDLVZWGxEKe6C by azonenberg@ioc.exchange
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       Here's 2.5 Gbps. Sync still looks near perfect. Can we push further?
       
 (DIR) Post #AwHuHFfO6nXpSUSYRk by azonenberg@ioc.exchange
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       Eh, 2.5 Gbps is probably the limit before the WaveRunner waveforms start looking ugly (it's only a 4 GHz scope).Let's do some signal processing here.You can clearly see the waveforms are coming from two scopes with a skew in acquisition time, but are perfectly aligned for the overlapping region.
       
 (DIR) Post #AwHuHH2oz9spjSQmbw by azonenberg@ioc.exchange
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       And here's the beauty shot I was going for.2.5 Gbps differential PRBS-31 split across two scopes of different models, plotted on a single timeline, and running filter graph blocks seamlessly on waveforms from each scope.