From Oscilloscope to Wireshark: A UDP Story (2022)
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From Oscilloscope to Wireshark: A UDP Story (2022)
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Re: From Oscilloscope to Wireshark: A UDP Story (2022)
#2> I configured the oscilloscope to collect 100M samples at 1 TSPS
Typo? I didn't think we had sample rates anywhere near that high!
Re: From Oscilloscope to Wireshark: A UDP Story (2022)
#3> I configured the oscilloscope to collect 100M samples at 1 TSPS Typo? I didn't think we had sample rates anywhere near that high!
A Keysight UXR can do one quarter of that, 256GS/s, but a Tektronix 6 series is limited to 25 GS/s iirc, so you're right.
Re: From Oscilloscope to Wireshark: A UDP Story (2022)
#4> I configured the oscilloscope to collect 100M samples at 1 TSPS Typo? I didn't think we had sample rates anywhere near that high!
> Random equivalent-time sampling takes advantage of the nature of a repetitive signal by using samples from several trigger events to digitally reconstruct the waveform. Since sampling occurs on both sides of the trigger point, pretrigger capability is very flexible. Because repetitive signals are being sampled, the bandwidth of an equivalent-time scope can far exceed its sample rate.
https://www.tek.com/en/documents/application-note/real-time-...
Re: From Oscilloscope to Wireshark: A UDP Story (2022)
#5> I configured the oscilloscope to collect 100M samples at 1 TSPS Typo? I didn't think we had sample rates anywhere near that high!
> Random equivalent-time sampling takes advantage of the nature of a repetitive signal by using samples from several trigger events to digitally reconstruct the waveform. Since sampling occurs on both sides of the trigger point, pretrigger capability is very flexible. Because repetitive signals are being sampled, the bandwidth of an equivalent-time scope can far exceed its sample rate. https://www.tek.com/en/document…
Here's a more specific example: PicoScope 9400 series supports just 500Msps per channel, however it's advertising "70ps transition time and 1TS/s (1ps resolution) random equivalent-time sampling", this sort of "equivalent sampling" is presumably where that seemingly crazy spec comes from.
Re: From Oscilloscope to Wireshark: A UDP Story (2022)
#6> I configured the oscilloscope to collect 100M samples at 1 TSPS Typo? I didn't think we had sample rates anywhere near that high!
A Keysight UXR can do one quarter of that, 256GS/s, but a Tektronix 6 series is limited to 25 GS/s iirc, so you're right.
Looks like max 50GS/s per their site. That also looks reasonable with the screenshot they have in the article showing 1ns / div horiz. But clarity on the data would be lovely. =)
Re: From Oscilloscope to Wireshark: A UDP Story (2022)
#7Earlier quoted context omitted.
A Keysight UXR can do one quarter of that, 256GS/s, but a Tektronix 6 series is limited to 25 GS/s iirc, so you're right.
Looks like max 50GS/s per their site. That also looks reasonable with the screenshot they have in the article showing 1ns / div horiz. But clarity on the data would be lovely. =)
Actually I take it back:
For the series 6B spec page...
Real-time: 50 GS/s (2 channels), 25 GS/s (4 channels), 12.5 GS/s (> 4 channels)
Interpolated: 2.5 TS/s
Re: From Oscilloscope to Wireshark: A UDP Story (2022)
#8[deleted]
Re: From Oscilloscope to Wireshark: A UDP Story (2022)
#9> I configured the oscilloscope to collect 100M samples at 1 TSPS Typo? I didn't think we had sample rates anywhere near that high!
> Random equivalent-time sampling takes advantage of the nature of a repetitive signal by using samples from several trigger events to digitally reconstruct the waveform. Since sampling occurs on both sides of the trigger point, pretrigger capability is very flexible. Because repetitive signals are being sampled, the bandwidth of an equivalent-time scope can far exceed its sample rate. https://www.tek.com/en/document…
But you can't use equivalent-time sampling for something non-repetitive like network packets.
Re: From Oscilloscope to Wireshark: A UDP Story (2022)
#10Earlier quoted context omitted.
> Random equivalent-time sampling takes advantage of the nature of a repetitive signal by using samples from several trigger events to digitally reconstruct the waveform. Since sampling occurs on both sides of the trigger point, pretrigger capability is very flexible. Because repetitive signals are being sampled, the bandwidth of an equivalent-time scope can far exceed its sample rate. https://www.tek.com/en/document…
But you can't use equivalent-time sampling for something non-repetitive like network packets.
For measurements like this the SDK will usually include some utilities to send the same data over and over on a port.