I'm getting communications errors when trying to capture data with my OLS. It seems mostly to happen with the larger recording sizes (64K and above) but sometimes with smaller sizes. It also seems more common with higher sampling rates (100KHz and higher). The symptom is a dialog box popping up (usually when the progress bar is fully to the right but sometimes part way through) which says
Communications Error
Error while trying to communicate with the device:
...
Make sure the device is:
-connected to the specific port
etc etc
At this point, even if I try more times and the scan succeeds, no data is displayed. (the traces are displayed but they are all ground).
I've tried using lower port speed, reseting the OLS, only capturing one channel, changing the pins I'm using on the OLS (buffered and non-buffered etc) and trying a different computer. But I'm still getting this behavior pretty often. I've mainly been using a Windows XP SP3 machine although I've tried a Windows 2000 machine as well.
Any ideas what is going on?
The sample sizes are limited - by default you can capture 32 traces at 4k depth - see http://dangerousprototypes.com/forum/in ... 47#msg4447 (http://dangerousprototypes.com/forum/index.php?topic=505.msg4447#msg4447)
[quote author="alanbur"]
The sample sizes are limited - by default you can capture 32 traces at 4k depth - see http://dangerousprototypes.com/forum/in ... 47#msg4447 (http://dangerousprototypes.com/forum/index.php?topic=505.msg4447#msg4447)
[/quote]
That is true as is made clear in the topic you quote. However, it does not appear that the communications problems are related to incorrect sample sizes. Even with the appropriate bitstream and correct sample size, the communications problems still occur sporadically. I've not sorted out any exact pattern although they do seem to be more frequent with higher sample frequency.
And for whatever reason, the communications problems seem much less frequent on a Mac so it isn't much of an issue for me now that I've got SUMP working on my Mac.
See http://dangerousprototypes.com/forum/in ... 80#msg4780 (http://dangerousprototypes.com/forum/index.php?topic=545.msg4780#msg4780)
I thought of a possible issue with USB->serial latency for boards that have intermittent response problems. If possible, could you please test this solution and see if it helps at all:
http://dangerousprototypes.com/forum/in ... opic=549.0 (http://dangerousprototypes.com/forum/index.php?topic=549.0)