[etherlab-users] AL state change problems with Copley Xenus Plus

[Keith Rogers]

I am new to ethercat and am experimenting with IgH EtherCAT master 1.5.1 
on Ubuntu 10.04. We're using it for Copley Xenus Plus motor controllers. 
I have some questions regarding application layer state control. To 
begin with, here is a quote from the controller's programmer's manual, 
pg 41:

"The following [AL] states are defined for the Copley Controls CANopen 
amplifiers: Pre-operational, Operational, Stopped."

Note there is no Safeop state. When ethercat master tries to set that 
state, I get the (PREOP + ERROR) error message I've seen in the archives 
here. I looked at the SII record and the enable_safeop flag was set, 
which is obviously a bug on Copley's part. Still, I thought if I could 
clear that bit, master stack would not attempt to go into the safeop state.

First problem: though the command line sii_read produced a file I could 
hex edit to clear the bit, sii_write failed to change the entry in the 
controller. dmesg shows the write was successful, but the controller's 
record did not alter. Whatever mechanism sii_write uses, it doesn't 
facilitate a change in flash memory on the Copley controller.

Second problem: since I couldn't correct the source, I sabotaged the SII 
read in slave.c (ec_slave_fetch_sii_general) by simply commenting out 
the assignment, leaving the previously memset 0 data intact. This did 
result in enable_safeop=no, but unfortunately ethercat master *still* 
tries to go into safeop the first time ecrt_master_send is invoked. Why 
does the master stack try to go into a state it has been informed does 
not exist?

Third problem: I must have a fundamental misunderstanding of ethercat, 
because I thought there would be a really obvious method exposed in the 
user library named something like 
"ecrt_slave_config_request_al_state_change" that I could use to request 
the slaves go directly to OP state. Or for that matter, allow me to 
control AL state within the application realtime as may be needed. I 
can't find any such method. Are applications not "supposed" to control 
AL state outside of the master thread? Or am I just blind...?

I'm at a loss of how to proceed. Suggestions welcome.

Keith Rogers

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.etherlab.org/pipermail/etherlab-users/attachments/20120410/9f0a181d/attachment-0003.htm>