Re: STG and Parallel Port

[Paul <paul.corner-at-tesco.net>]

Hi Les (& Bill)

On Monday 18 Nov 2002 1:27 pm, Les Watts wrote:
> However I also need information on spindle ,lube,and coolant inputs
> for EMC. Searches have given little information but reading source
> code comments have given me bit more.

There are some notes in the BDI-EMC Handbook - You can grab the latest 
handbook rpm from www.linuxcnc.org/bdi/RPMS/rpm.html

> 1) Activate programmable spindle control. Right now the spindle is
> manual. Start a program without the spindle on and there will be
> a world of grief.

There has been a few additions to the CVS code to allow for spindle speed 
control via a spare DAC.

> Right now commands like M3 in a program cause
> a halt so I have to strip them out. It seems like EMC is stopping
> and waiting for something... perhaps a lube sense?

I've not seen this happening... One thing I have noticed though, if no S word 
is used in the same block as an M3/M4, the spindle outputs remain inactive. 
The only time an M3/M4 will work without an S word is if one has been used 
earlier in the program.

> So far it looks like no one
> is using the stg i/o for this so it must be on a parallel port.
> Is it the one I specify in the .ini? Is there a pinout? Is spindle
> fwd/reverse etc tied to lube sense? 

If you cycle through the "Toggle Labels" button in IO_Show, you'll 
eventually get the default IO assignments for bridgeportio appear. These can 
be reassigned in the ini file - Look for things like FLOOD_COOLANT_INDEX and 
it's counterpart, FLOOD_COOLANT_POLARITY. the former specifies which IO pin 
(or index) is used, and the latter, the active state polarity.

> 2) Spindle force monitoring. I said in the past I wanted to do this
> and it looks like the little circuit design works.

This looks like it should be tied in to the E-Stop system, with perhaps a pin 
to monitor the state so that an error box can be popped up.

There are a number of areas that can be improved upon as far as general 
purpose IO is concerned. I'm slowly working getting some of the basic IO 
routed through an STG II card, but only having 32 pins available is limiting.
It would be nice to be able to assign the Home/Limit switches from the ini 
file, along with being able to set a particular group of pins as Inputs or 
Outputs dynamically. At present, this is all hard coded in to the sources...

Another area worth looking at is a ladder type PLC interface for the IO 
control :-
http://www.sourceforge.net/projects/classicladder or :-
http://www.multimania.com/mavati/classicladder
Some work would need to be done with the code to add hooks to allow 
communication between it and EMC.

Oh, one last challenge - A snappy name is needed for this IO controller. If 
it all works, it should be able to use the same hardware as emcmot, be it Jon 
Elson's hardware, the STG, StudioFerraris, or Vigilant cards. Even the same 
parallel port used for Step/Dir could be used for basic spindle control..

Regards, Paul.