EtherCAT with single-board RIO

[maciek.na]

Hi,

I wondered whether single-board RIO in any of the configurations supports EtherCAT communication. The area of application I am looking at is mobile robotics/vehicle control. I need to run a program on a master that executes control algorithms based on data from multiple sensors in the vehicle. The needed bandwidth is quite high (min 2.4 Mbps with main control loop executing at 2 kHz) While the Master Controller can be quite bulky, the slaves (nodes) would have to placed at various locations at the vehicle and weight/space saving is crucial. I wondered if I can use Single-Board RIO for such setup. I would welcome any ideas.

Best regards,

Maciek

[Aix-La-Chapelle]

Hi Maciek,

The SOM supports NI-Industrial Communications for EtherCAT.  You would need to design a carrier board to utilize SoM in your specific application.  As for the 2kHz execution loop, there are multiple factors to determine if this is possible, but given benchmarks the EtherCAT team has run, the fastest achievable speed 350 us with 9 bytes of data.  You may be able to achieve this speed depending on the amount of data you're attempting to push through the network.  However, these benchmarks were performed only running the EtherCAT master code, with no other RT application running.  This will have an effect on the execution loop you can achieve.

[maciek.na]

Hi Matt,

Thank you for the respose!

This is very interesting. Could you please provide a link to the benchmark you are reffering to?

Best regards,

Maciek

[Aix-La-Chapelle]

Hi Maciek,

Apologies I didn't post it with my original post.  This is because I hadn't publised the paper yet, but it is up now!  Please take a look.

[maciek.na]

Hi Matt,

Thank you for this! The benchmark results look very good.

I wondered also what type of devices  can act as EtherCAT slaves. Would it be possible to have Beckhoff, who is inventor behind EtherCAT (provides 50 V  DC motor drives that I am interested in), as well as the SOMs acting as slaves  under control of NI cRIO-9033 or cRIO-9082 masters? As much I would like to run algorithms written in LabView, I am interested in interoperabity between NI and Beckhoff hardware.

Best regards,

Maciek

[Aix-La-Chapelle]

Hi Maciek,

No problem!

National Instruments provides the NI 9144 as an EtherCAT slave.  This is NI's only EtherCAT slave.  The NI-Industrial Communications for EtherCAT driver only provides a master stack, so the SOM can only act as an EtherCAT master with the driver.   Our NI-Industrial Communications for EtherCAT master stack may be used with 3rd Party EtherCAT slaves.  

Please let me know if you have any additional questions.  Thanks!