andy pugh wrote:
> I assume that you are already using one of these
> http://www.linuxcnc.org/docs/html/man/man3/RTAPI_MP_ARRAY_STRING.3rtapi.html
> To set the existing option. You probably need to either parse that
> string for an additional code, or add another parameter set.
> If it is optional and there is a reasonable default for existing
> installations then RTAPI_MP_ARRAY_INT might work.
> This bit of code here is how Seb did it in the Hostmot2 driver (which
> takes several different command line switches)
> http://git.linuxcnc.org/gitweb?p=linuxcnc.git;a=blob;f=src/hal/drivers/mesa-hostmot2/hostmot2.c;h=ee9ca27f0d50791cbae83e4291b7f2ce3a66df10;hb=HEAD#l313
>
>   
The problem is this setting can apply to a specific board in a system with
multiple boards.  it would not necessarily be a global setting for the 
entire
driver.  So, the hal_ppmc.c driver can theoretically talk to 24 boards
on 3 parallel port addresses.  The driver now uses the
RTAPI_MP_ARRAY_INT scheme.

I'm gathering that in the code you link to, these parameters are global to
that invocation of the hostmot2 driver.  The complication in the ppmc
case is they could be specific to one of several boards.


Well, the scheme I mentioned of encoding the setting into the bit field
that specifies par port and slot number starts to look better.  I know of
NO system where multiple par ports are used with the PPMC driver,
but I do know of some systems with multiple PWM controllers on
one parallel port, and of course the PPMC boards all have multiple
boards per system (encoder, DAC, DIO).  I'm not sure how many
people will be using this fairly arcane feature, anyway.  You'd
only need it where the encoder count rate exceeds 500K or so.

Thanks,

Jon

------------------------------------------------------------------------------
This SF.net email is sponsored by Windows:

Build for Windows Store.

http://p.sf.net/sfu/windows-dev2dev
_______________________________________________
Emc-developers mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/emc-developers

Reply via email to