Yocto Linux for Rpi3 + netHAT

[jenrei]

Hallo together,

as I understand from another topic in the forum it is feasible to use a generic Rpi3 + netHAT in order to have a netPI RTE like device. Is it also possible to use the RT-patched Yocto Linux used on netPI on the raspberry or just a generic Linux OS with docker?
I want to test what I can to with the POWERLINK and Codesys before investing in a netPI. For example I guess there will also be the slave only issue decribed by others for other fieldbuses.

thanks in advance
Reinhard

Rpi3 + netHAT Topic:
https://www.netiot.com/forum/?tx_typo3fo...f6095b1138

[Armin@netPI]

as I understand from another topic in the forum it is feasible to use a generic Rpi3 + netHAT in order to have a netPI RTE like device. Is it also possible to use the RT-patched Yocto Linux used on netPI on the raspberry or just a generic Linux OS with docker?

Hello Reinhard, yes this is correct. While netHAT is made more for "students" and show the use case EtherCAT, EtherNet/IP and PROFINET as slave device in a simple manner with fixed I/O length of 32bytes input and output, netPI is more flexible and allows to configure any possible I/O length. But neither for netHAT nor for netPI we provide POWERLINK support today.

Using Docker has no need for YOCTO linux as used on netPI. Docker can be installed on native Linux as described here https://www.raspberrypi.org/blog/docker-...pberry-pi/. I am running it at home on my Pi too. But what you must know is that netHAT uses netX52 network controller and netPI uses the netX51 chip. Both have the same chip die, but since they are different chips, different firmwares are used to be loaded into them. So not all firmwares that are available for netPI and netX51 are available for netHAT and netX52. For example on netPI the netX network controller can be standard ethernet ... for netHAT we never compiled this firmware.

I want to test what I can to with the POWERLINK and Codesys before investing in a netPI. For example I guess there will also be the slave only issue decribed by others for other fieldbuses.

This question you have to explain closer to me. You have Codesys that you can run on any Raspberry Pi, this is ok for me, but how is it about POWERLINK. Do you want Codesys to run POWERLINK stack or netPI/netHAT POWERLINK the stack? Is is POWERLINK slave or master you are talking about

Armin

[jenrei]

Hello Armin,

thanks for the fast answer!

Using Docker has no need for YOCTO linux as used on netPI. Docker can be installed on native Linux as described here https://www.raspberrypi.org/blog/docker-...pberry-pi/

I was aware of that but just didn't want to miss out, if easily possible, on netX specific optimizations and/or realtime patches. But for testing purposes it should be no further issue.

This question you have to explain closer to me. You have Codesys that you can run on any Raspberry Pi, this is ok for me, but how is it about POWERLINK. Do you want Codesys to run POWERLINK stack or netPI/netHAT POWERLINK the stack? Is is POWERLINK slave or master you are talking about

I'm running this https://store.codesys.com/powerlink-conf...ditor.html on my raspberry to connect to B&R. It configures the raspberry as managing node (master). So I'm in need of a second ethernet port and netHAT seems a good way to provide that.
As you described

For example on netPI the netX network controller can be standard ethernet ... for netHAT we never compiled this firmware.

this is/will be and issue.

thanks
Reinhard

[jenrei]

That was very helpful! I will consider all options.

thanks
Reinhard

[Armin@netPI]

Here the exact explanation: if you dig into all details about netPI's Ethernet based firmware you will detect that we are providing it as a PROFINET IO device/Ethernet combo firmware where just the PROFINET part is disabled/remaining unused.

The combo firmware consumes so much RAM space that it can run on netX51 controllers only using external RAM like it is populated on netPI. netHAT has a netX52 controller only that can't connect to external RAM, so this combo firmware will never get running on netHAT from the physical point of view ... and now comes the point: there is no alternative, we never developed an Ethernet only firmware that could consume less RAM. So for you the netHAT will remain unusable for your kind of application.

But buy a netPI at amazon and if it doesn't work for you and your application just send it back. But before I would containerize the POWERLINK thing on your Raspberry to be able to run it on netPI with zero effort later.