Hi,
I’m looking for the cause of some sporadic
overload notifications with one of our usb devices. When I analyze the overload
in the IO Cycle Telemetry window, I see that there is a large diff between the main
‘Start’ timestamp (next to the UI arrow) and the ‘->Cycle”
timestamp (about 1ms). This diff appears to be the cause of the overload,
because all the other timestamp diffs look reasonable (and are the same as in other
non-overload cycles.)
Here’s a snippet of the first few entries on
the first 2 lines (the V represents the UI arrow):
V 93327.517 ( +2.663 +0.030)
->Cycle:
34993 93328.604 ( +0.000)
The diff between 93328.604 and 93327.517 is what
appears top be causing the overload. In all other non-overload cycles this diff
is much smaller, typically .003 ms.
So it looks as if something is pre-empting the
IOProc, but it always happens at the same place, ie right at the very beginning,
so I wonder of something else is going on.
One other difference that I see in the overload
cycle compared with the other cycles is that the Wake:samp time is later, it’s
181 samples on the overload cycle as compared to 128 samples on the succesful
cycles.
Thanks in advance, if any more data is needed let me
know.
-Ted