[Bdi4emc-help] configuring ini file

Paul bdi4emc at bulldoghome.com
Mon Dec 4 22:08:37 CET 2006


Hi David

On Monday 04 December 2006 04:26, David Szakovits wrote:
> On page 39
>    Master_User.pdf it says a full suite of home and limit switches can be
>    implemented with independent wires, if 2 more parallel ports are
>    added.

There is also a cross reference to page 30 of the Integrator.pdf doc that 
refers to another section on "Using the parallel port" - This last section 
appears to be missing.. Without some additional code, it would not be 
possible to use a second parallel port to read home or limit switches.

>    if there are 5 inputs, for a three axis machine, does it make sense to
>    have use 3 inputs for home switches and then combine the limit
>    switches?
>    Are the limit switches, useful for more than a safety feature for
>    turning the motors off in case of a mishap?

For any machine using all but the smallest of stepper motors, limit switches 
are an essential safety feature. Even a Sherline mill with the factory fitted 
stepper motors can suffer damage if the table is run to the limit of travel 
at high speed.

As to the question of common home switches, homing each axis in sequence is 
not a major chore and only needs to be done once on power up.. 

>    In EMC(1). are the pinouts customized by changing configuration files
>    or is it more involved?

Unfortunately, the pinouts are hard coded - If you are familiar with the 
process of compiling, the changes are fairly minor.. For the parallel port 
driver, the file to edit would be extsmmot.c in the src/drivers directory.
 Not a very satisfactory solution if you do not know C - User defined pinouts 
has been on the cards for a long while, it was what prompted HAL until it 
went off the rails.

If you can bear with us for a while longer, the configuration files will be 
revamped and the issue of user defined pinouts addressed - Multiple parallel 
ports had not been considered, but it should probably be added to the list at 
some stage.


Regards, Paul.




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