Re: Re: EMC Encoders

Jon and other EMC folk

From: Jon Elson <elson@...>
<s>

>Is the BDI completely stable for you? I've just had it up a week, and
>I've gotten the system to hang 3 times already!

The most troublesome bugs are gone in the latest sourceforge code. There
is an additional problem with rtlinux-2.0+ that I find partictularly
troublesome while I am developing software for the EMC. Each time the EMC
shuts down, there is a small chance that one of the real time linux modules
that is used by the motion stuff may hang around. This module, mbuff, is
used to allocate the shared memory area for the motion processes. The
author of mbuff says,

" issues:
- using this method, it is *really* easy to get dangling
mbuffs, i.e., mbuffs that nobody owns."

The most recent EMC run scripts attempt to remove mbuff along with other
modules but ocasionally it is not successful. That mbuff will continue to
work with the EMC on subsequent starts but it will eventually build up
errors and cause problems.

If you are in the business of making parts and come out to the machine and
start EMC up, work awhile, and shut it down, you will never see this
problem. But those of us who start and stop the EMC a hundred times a day
will often see it.

HTH

Ray