jjoonathanParticipantjjoonathan April 9, 2021 at 2:27 pm
I’d like to clarify the intended behavior of USB 2.0 with the SM200B. I know it isn’t specified, but informally speaking is it supposed to not enumerate at all under USB 2.0 or is it supposed to enumerate and connect to spike with reduced performance and red “USB” text on the graph to indicate what is happening?
I have been using my SM200B with a PC that supports USB 3.0, and it works great, but it would also be nice to use the SM200B from my PC-based oscilloscope that runs Windows 7 and has USB 2.0 ports. It lives on my bench rather than next to my bench and sometimes when probing around that’s a very convenient arrangement to have. Reduced functionality and slower speed would be acceptable tradeoffs. The SM200B doesn’t seem to work at all with USB 2, though. I thought this was an intended limitation until earlier today I saw red “USB” text in the Spike spectrogram view and hwinfo reported that the link had degraded to High Speed — but the spectrum view remained working. I would be happy with that state of affairs if I could use the SM200B from my scope!
I can sympathize with the design choice to drop USB 2 support completely, but I want to make sure it’s actually a choice rather than a silly bug, because USB 2 support would be useful to me.
Justin CrooksModeratorJustin Crooks April 9, 2021 at 3:35 pm
Unfortunately we do not support USB 2.0 speeds with the SM200B. While I can see the benefit of the convenience, the capabilities would be tremendously reduced at USB 2 transfer speeds, and it would be a very large firmware change, so we opted not to add the support at all.
jjoonathanParticipantjjoonathan April 9, 2021 at 3:42 pm
That’s fair, thanks for clarifying.
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