Re: Re: Software Question...

Hi Jeff

You are right on about the PC not knowing about a crash. The least cost
solution to using real PC closed loop motion control is the EMC. You
said earlier that you were looking for a multiple hundred dollar
solution. This one will cost several for the encoder reader and D/A card
so it will fit your specifications. Matt Shaver posted a list of sites
that you could look at for boards. If the BDI doesn't cost enough you
can send extra to Paul or me or one of the other developers.<g>

There are two big reasons that I can think of for using full feedback
motion control. The first is that you can adjust the following error
settings for the machine that you are using and it will track or present
you with an error message that stops it. The second is that the kind of
motion that you will get from the motors approaches velocity control
rather than position control. Full servo control connected to a good
machine will give better surface finish on long shallow tapers and near
the quadrants of a milled circle.

Ray

>    From: "jeffalanp <xylotex@...>" <xylotex@...>
> Subject: Re: Software Question...
>
> Hello Bill,
>    If you are using Master5 (or Mach1) and sending the output (step &
> dir) to an amplifier like the G320, the software WILL keep plugging
> along even if the machine has crashed (the servo loop is closed at
> the amplifier).  But, a crash would typically cause the amplifier to
> Fault out, so you could feed the Fault from the amp back into the
> software control via E-STOP or some other mechanism.
>
> > SO, If the software does not receive a signal from the motor or
> > encoder, the 'loop' closes at the driver? The software (Mach1
> > example) just keeps on plugging commands to a crashed machine/part?
> > 
> > Bill C.