[etherlab-users] Slave register access

Florian Pose fp at igh-essen.com
Wed Nov 5 16:46:14 CET 2008


On Wed, Nov 05, 2008 at 09:11:18AM -0500, William Montgomery wrote:
> I am a newbie with respect to ethercat so I am not sure of the best
> way to do this.  I would like to create a sync pulse on the slave for
> each write to the slave.  I have found that I can write to a register
> on the slave controller to cause this pulse.  I can modify the eeprom
> on the slave to add another sync manager and pdo for this but was
> unsure if I should use mailbox or buffer method to access the
> registers.  After further reading, I thought that the whole PDO/sync
> mgr approach might not be necessary and that I could bypass that
> mechanism with a more direct method.

This is indeed the usual way. Create a sync manager configuration (in
buffered mode) with at least one Pdo containing a Pdo entry. You can
check the Pdo configuration that the master read by calling 'ethercat
pdos'.

Then you can register that Pdo entry via the API and exchange it
cyclically (like in the minimal example), then the sync pulse should be
generated on every access.

-- 
Best regards,
Florian Pose

http://etherlab.org



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