[Etherlab-users] Communicate with slave via terminal

Gabriel Forstner gabriel.forstner at corpowerocean.com
Tue Feb 23 18:24:22 CET 2021

Dear etherlab-users,

I am quite new to the use of ethercat in linux and struggling to get a particular slave from state PREOP to OP, and to read values of this slave. I have found some commends on this topic already, where it is suggested to do a “reg_write” at “0x500 -tbool 1”. Other suggested to generate a SII file out of an XML file with TwinCAT and to download it to the slave. I did both but without success. The slave I am struggling with is an absolute encoder, and the problem might be related to the memory architecture of the EEPROM.

I am using “ethercat version IgH EtherCAT master 1.5.2” on “Ubuntu 20.04.2 LTS” with “uname -r 5.4.84-rt47” kernel.

First, I am wondering if it is required to have an application in order to communicate with slaves or is this also possible via the terminal. I can do the following in the terminal:

  *   When I enter “sudo ethercat slaves” all connected slaves a listed, so I assume that the bus topology is correctly recognized.
  *   I can list all sdos with “sudo ethercat sdos -p0”, e.g., SDO 0x6004, "Position value" 0x6004:00, r-r-r-, uint32, 32 bit, "SubIndex 000".
  *   I do not receive the correct position values, e.g., when I read the position sdo with “sudo ethercat upload -p0 -tuint32 0x6004 0” I receive “0x00000000 0”. When I enter ”dmesg” I receive three error massages: “SDO download 0x6004 (4 bytes) aborted.”, “SDO abort message 0x06010000: "Unsupported access to an object".”, and “Failed to process SDO request.”. However, a meaningful value is displayed in TwinCAT.
  *   I cannot change the state of the slaves to OP via the terminal.

Second, I am wondering if the reg_write can be done in the terminal (which appears not work in my case):

  1.  Change state “sudo ethercat state -p0 INIT” works.
  2.  Do “sudo ethercat -p0 reg_write 0x500 -tbool 1” appear to work.
  3.  Change state “sudo ethercat state -p0 PREOP” works.
  4.  Change state “sudo ethercat state -p0 SAFEOP” does not work. When I enter ”dmesg” I receive two error massages: “Failed to set SAFEOP state, slave refused state change (PREOP + ERROR)” and “AL status message 0x001E: "Invalid input configuration”.”.

I would appreciate it a lot if somebody could answer me my question!

Kind regards,

[cid:image002.png at 01D70A10.3B96EBE0]Gabriel Forstner, Senior Software and Automation Engineer
CorPower Ocean
Västberga Allé 60, 126 30 Hägersten
M: +46 73 155 88 88

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.etherlab.org/pipermail/etherlab-users/attachments/20210223/374b3dbb/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.png
Type: image/png
Size: 3177 bytes
Desc: image001.png
URL: <http://lists.etherlab.org/pipermail/etherlab-users/attachments/20210223/374b3dbb/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.png
Type: image/png
Size: 3460 bytes
Desc: image002.png
URL: <http://lists.etherlab.org/pipermail/etherlab-users/attachments/20210223/374b3dbb/attachment-0003.png>

More information about the Etherlab-users mailing list