Re: kernel2.2.13 and EMC

Ian Wright wrote:

> [Jon] in one of today's posts you refer to 'backing off the interrupt rate'
> to cure refresh rate problems. This was something I noticed with my previous
> installation of EMC in that the screen flickered continually and annoyingly.
> Can you be a little more specific as to how you 'back off the interrupt
> rate', it may be useful if I have to drop back to a 2.0.36 version.

I don't know if this is your problem. There was something in a previous
message (from you?) about very slow updating of the screen display.
That could be a sign of real-time overload. You would reduce the
rate at which the RT task is executed, by changing several lines in the
<whatever>.ini file that sets all the system-specific parameters of your
EMC installation. The most likely parameter would be the CYCLE_TIME
setting for each axis. If you make this time larger, it will execute the
calculations less frequently, reducing CPU load.

But, monitor flicker may be another problem, entirely. It could be
magnetic interference from motors in your machine tool, or it could
be a low frame rate, which would need to be looked into with the
xvidtune utility that is a part of the XFREE86 environment.
It will tell you the video frame rate (equals vertical refresh rate in
Hz). If it is well below 60 Hz, that would certainly cause such a
visible flicker. One other possibility is that you are using a high
resolution mode in interlace, and any pattern that comes up on the
screen with alternating light and dark horizontal lines will appear
to flicker very badly. If this is what the case is, change your screen
background.

Jon