Here is more input on my original question below.
Our DNC seems to be acting up lately.  Some machines refuse to download
from the DNC, instead requiring a copy of the drill file be loaded from
a disk.
We also experienced a defect where one unique hole (on several panels)
had drilled at .0135 diameter instead of the correct diameter of .031.
If this had been a kitting error, then many holes would have been
drilled undersize. We know the drill file was correct before download.
Therefore, if this was some kind of data transmission error, then what
might have gone wrong in our system?  Could there be some kind of
impedance matching problem?  Do we have too many machines hooked up to
the data cables?  Have our nodes gone nuts?
Any suggestions would be greatly appreciated.

Drilbert



drilbert wrote:
>
> We have experienced an intermittent missing hole (not drilled) defect on
> one part number.  On each of 20 panels I have analyzed, the same hole is
> missing.
> The entire drill file is intact on the mainframe, however, some kind of
> glitch must be occurring either during downloading the data across the
> DNC or executing the program on the drill machine.
> We use Hitachi drill machines.
> Has anyone run across such a problem, or does anyone have an idea what
> might be the cause of this mystery?
>
> drilbert