[etherlab-users] Sync problems and DC mode

[Ignacio Rosales Gonzalez]

Hello,

First of all  many thanks for your help!


If you look below, master->app_time is not really used in the code.
I get the dc ref slave clock with
ecrt_master_reference_clock_time(master->master,
&master->reference_time); and save in master->reference_time

after that

 ecrt_master_sync_slave_clocks(master->master); // sync slaves to ref clock
 ecrt_master_application_time(master->master,
master->reference_time+master->app_time_period); //update master time with
time got from dc ref slave

Could you help me with the Sync0shift values??  The topology of my network
is line one.

Master ----- S1 - S2 - S3 ..... and so on until S25.

I suppose I must set a very small one for the first slave and increase it a
little for the next ones, no??

The kernel is Linux debian 3.4-9-rtai-686-pae #1 SMP PREEMPT Debian
3.4.55-4linuxcnc i686 GNU/Linux
what is the default one of the linuxcnc 2.7 debian wheezy

The network card is a realtek r8169

Thanks again
Regards,

Ignacio Rosales






2018-01-23 2:06 GMT+01:00 Boris Skegin <boris.skegin.de at googlemail.com>:

> Hello.
>
> > With this version
> > <https://github.com/narogon/linuxcnc-ethercat/commit/
> e4ab86ba6167ced532e49904059df580062b2d97#diff-
> 059a684a933530837771b5a249433ff3>
> > (also as attachment lcec_main.c) I get the servos sync and OP but it
> seems
> > that the PDO doesn't arrive for some of the slaves (no idea why).
>
> master->app_time += master->app_time_period;  means that you just sum
> up constant cycle times of  the LinuxCNC thread. So any latency
> information gets lost here.
>
> Rather  make  master->app_time  be equal to something like
> rt_get_time() transferred to EtherCAT time.
>
> I also think that a proper value for sync0Shift  can help a lot.
>
> If however nothing of that helps, then proceed  to  Graeme Foot's option
> b) .
>
> BTW, what exactly is your kernel and network card and do you really
> use an adopted ( non-generic) network driver?
>
> Regards,
> boris
>
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