[etherlab-dev] Multiple mailbox protocols and other issues

Knud Baastrup kba at deif.com
Tue Feb 3 08:08:13 CET 2015

Yes, I decided not to use the alias as matching criteria for the slave data due to the "tree points" intended use of aliases. Currently we do not use aliases on our modules, but we are planning to introduce this in the near future to prevent that some modules get the wrong configuration if a rack of modules (with same vendor and product code as the following rack) are disconnected due to wire/power break. What do you mean by the "master configurator" ?

BR, Knud

-----Original Message-----
From: etherlab-dev [mailto:etherlab-dev-bounces at etherlab.org] On Behalf Of Gavin Lambert
Sent: 3. februar 2015 02:00
To: 'Graeme Foot'
Cc: etherlab-dev at etherlab.org
Subject: Re: [etherlab-dev] Multiple mailbox protocols and other issues

On 3 February 2015 13:38, quoth Graeme Foot:
> Sent: Tuesday, 3 February 2015 13:38
> To: Gavin Lambert; 'Knud Baastrup'
> Cc: etherlab-dev at etherlab.org
> Subject: RE: [etherlab-dev] Multiple mailbox protocols and other 
> issues
> From: etherlab-dev [mailto:etherlab-dev-bounces at etherlab.org] On 
> Behalf Of Gavin Lambert
> > On 2 February 2015 20:18, quoth Knud Baastrup:
> > > 16_improved_ethercat_rescan_performance.patch:
> > > The SII data and PDOs will now be stored when the EtherCAT master 
> > > is in
> > its
> > > operation phase. The stored SII data and PDOs will be detached 
> > > from the slaves prior to a scanning and re-attached during the 
> > > scanning without the need to fetch the SII data and PDOs once 
> > > again. The SII data and PDOs will however only be stored if the 
> > > slave have a serial number defined as this serial number will be 
> > > used when re-attaching
> SII data and PDOs.
> >
> > Ooh, thanks for that one.  That's one of the performance holes that 
> > I
> planning on investigating myself soonish.
> >
> None of my modules seem to have serial numbers (Beckhoff IO and 
> yaskawa amps), or is that a bug that's got a patch?  I'm running the 
> original
> (+ misc patches).

It's not a bug, or really related to the master software at all.

It's up to the device manufacturer whether a given device has a serial number or not.  In my case they do, but I'm mostly using in-house hardware.
Beckhoff modules as a general rule don't seem to have serial numbers.

This is separate from the "alias" which is used in network addressing and is typically (but optionally) set by the network designer via the master configurator.  The EtherLab master lacks specific commands to set aliases but it can recognise aliases set by other masters, and some slaves support a CoE download to reconfigure their alias (which can be accessed via the command line), and some others have dipswitches.  Generally aliases are only needed at "tree points" in the network graph, so if you're only using simple chains they're less useful.

Technically the serial number can be altered by the master / network designer as well via an EEPROM download, but this is less "encouraged".

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