Head Bottle Washer

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's contributions
    • I have several Windows 7 machines with USB 3 ports: an HP laptop with built-in USB3 ports and a desktop with an add-in card. Those drivers are apparently not native to Win 7, but the result is the same (people are running USB3 on Win XP). I develop imaging applications and typically get around 2.4 Gb/sec real-world through USB3, using Opal Kelly FPGA boards. I'm sure there are driver differences but in my case the limitation is on the FPGA side. I think it would be very feasible to design a much better cheap logic analyzer, with a gig of DDR3, at least 32 channels, 200 MHz external sampling, USB3, trigger in/out, and support for triggering off the protocol analyzers (this seems to be lacking in all the inexpensive logic analyzers -- post-processing captured data doesn't count). FPGAs are big and cheap enough that this would be straightforward.

    • Agreed. The acceptable outcomes to get each face to appear only once for 6 rolls of a die are the permutations of (1,2,3,4,5,6), of which there are 6!. The total number of outcomes for 6 rolls is 6^6.

    • LogicPort, like Saleae, uses compression, so the 2K buffer is not as much of a limitation as it might seem. But it definitely is less than ideal -- sometimes I have to hide the frequently-changing signals (like clocks) from a view to get longer sampling times. Personally a logic analyzer with only 16 channels and 12.5 MHz sampling would be useless for me since I work mostly with much faster FPGA signals. The combination of LogicPort and internal Chipscope covers most of my bases. I'm not convinced about the reason for not using USB 3.0 -- it was released in 2008, and it would appear that the Logic16 is more recent than that (2011 maybe? If so I'm a bit confused about why it's called the "new" Logic16 in the review).

    • I've used the similar Intronix LogicPort for years. With 34 channels, 500 MHz sampling, and more flexible thresholds I think it's worth the extra ninety bucks or so. Now I'm waiting for a USB 3.0 version with significantly more hardware memory -- small sample storage is its Achilles heel. It would seem that the Logic16 relies mostly on PC-side sample storage (streaming data via USB after the trigger event?), which would be useful if you can live with slow sampling rates (12.5 MHz for 16 channels) but need to acquire more data than can fit in on-board storage. It's not clear why Saleae didn't go with USB 3.0 with its much higher bandwidth.