[EtherCAT] - Problems with a slave (EL6751)

[Javier]

Hello,

We are updating a test rig that is equipped with many ethercat Beckhoff modules. The idea is to develop a new LabVIEW software (LabVIEW RT) using the actual I/O hardware (Beckhoff). We have checked the communication between the NI-Ethercat Master and most of the modules, and we have a problem with a EL6751 module (CANOpen master). 

The problem is that when we try to switch the san engine to active and the EL6751 module is connected we receive the following  error:

  

If we go to EL6751 module we can see that the module was not able to change from init to pre-operational. See the attached picture

  

And what is more strange, if we search the module programatically we can discover (and send SDO) to all other devices except the EL6751, which not appear in list of slave devices discovered. If we use other Ethercat masters for other companies (Beckhoff, ESD..) we are able to run the Ethercat network and to configure all the modules.

 

We know that we have to configure the EL 6751 module properly to establish a real CANOpen communication (thing that we think to do by SDO), but we don't understand why the Scan Engine is not able to start correctly. One thing a little bit strange is that is the only module that hasn't any variable under the tree...

The configuration that we have been using is :

1. Industrial PC computer: Intel i7
2. Network Adapter: Intel Pro 100/1000 compatible device
3. NI Real-Time Phar Lap ETS 13.1
4. NI-Industrial Communications for Ethercat 14.5

It would be very helpful if someone can give some advise or recommendation ...

Thanks in advance.

[Miro_T]

Javier,

EtherCAT specifications defines many optional features for master and slaves. If master or slave is missing some functionality that other device includes, you might run into complications.

Since Beckhoff EL6751 slave works with Beckhoff master and does not work with NI master that might be the case here. In fact, I think EL6751 and EL6731 were reported as not compatible with NI master but no further explanation was provided.

First steps to determine what might be going wrong is to look at wireshark trace between master and EL6751. Here is a KB that shows how to capture EtherCAT packets. 

It would be ideal to run capture when master is attempting to switch slave into pre-operational mode. 

[Javier]

Hello Miro_T,

I will try to capture the telegrams but ...I'm not sure I will able to analize them. I will try.

Do you know where is the list of slaves that are reported to have problems with NI Master?

Thanks!!!

[karupinwendy]

Hi Javier,

I am sorry that NI has not maintained such a list of supported 3rd party slaves officially.

What I know is that the slave EL6751 you are using is a kind of Fieldbus Gateways device; and NI cannot support such device well.

Apart from EL6751, EL6731 cannot be supported either.

Wendy

[Javier]

Hi karupinwendy,

OK, thank you for the information. Anyway I will try to capture the communication between the master and the EL6751 and post it. 

If I've understood right, the NI Master will not be able to manage any kind of fieldbus gateway device, isn' it?. We are looking to other slaves  like https://esd.eu/en/products/can-ethercat , which is an other gateway device.

Best regards

[piashaw]

I know this is a very OLD thread, but did you ever find a solution to this?

[Yin_W]

Not sure when Javier will answer your question. Have you tried yourself? 

[piashaw]

Yes I tried and the EL6751 goes into error mode. Interesting the 6751-1001 (Can SLave) goes operational.

I have had untold issues with NI and ethercat and after many hours/days found ways around most of them eg adapting XML files in odd ways etc, but this is just trial and error as the NI error code is VERY unhelpful.

However if someone has already found a solution, no point in re-inventing the wheel.

If the EL6751 didn't work, did anybody find another fieldbus gateway which did?

Thanks