Re: Stg/Emc Jogging problem

["Keith R. Bolson" <krbolson-at-visi.com>]

Hello All -

  I will speak directly to the missed keyboard scan codes.  This
is a problem in commerical PC-based CNC implementations.
In a noisy electrical environment, keyboard release codes ARE
garbled and missed.  The keyboard spec uses two open-collector
lines - which is a wonderful way to pick up noise one can't
eliminate, especially on long runs.
  And a missed release code can lead to a run-away jog.

  Possible solutions include:
a)  use very short, shielded keyboard cables
b)  in software, when jogging, require auto-repeat
     say 100 ms else time-out the jog
c)  don't use the PC keyboard, try serial

Happy Easter  --krb