> On 9 Jun 2020, at 23:51, Stephen Bell <[email protected]> wrote: > > > The BBB would be the master for my use case, with devices such as servomotor > drivers as slaves in a dual-redundant topology. I use the BBB Wireless, and > thus don't have the onboard RJ-45.
If you want the bus to be redundant, the master indeed needs 2 connectors. In a normal non redundant setup all the wires make up a single ring. The master receives back its original datagram plus what all the slaves added to the ”train”. If there is a cable break, the master will never receive back the updated datagram. I would love the BB to be enabled with the ti pru-icss ethercat stack so it would act as a slave. Then maybe a HAL component similarly to the Hal-pru-generic component could exchange HAL pins with the ethercat bus. I tried working on that a few years ago, bought an AM437xIDK https://www.ti.com/tool/TMDSIDK437X but I didn’t get to the finish. I got stuck very quickly when trying to work out how to get the ethercat slave stack working in a Debian image. Robert Nelson helped a lot to get me to build an image, and that worked fine on that board/cpu. IIRC I got machinekit to work. But the PRU icss and ethercat was a bridge too far for me. iirc the ethercat slave stack code was made for an rtos so i had no clue where to begin. My lack of (domain) knowledge. Bas > The other industrial connections would also be necessary, particularly in a > push-connector form factor, rather than screw terminals (additional points if > they can be accessed when on a DIN rail). > > Isn't the BBB a 'popular MCU'? The thread is intended to take suggestions for > a new machinekit cape design, not alternative MCUs. But if an EtherCAT cape > is as trivial as you describe, send me a production sample and I'll pay a lot > more than 2 cents. > >> On Tuesday, June 9, 2020 at 4:25:43 PM UTC-4, Juha Heikkila wrote: >> Hmm out of curiosity why would you require 2 separate EtherCat ports or is >> it just for a ring topology? >> >> If you can settle for just one, you could run the igh EtherCat master stack >> on the BBB and use available LAN port. So if one is enough, no need to mixup >> the cape with the EtherCat stuff. >> >> ”Ideally” for an industrial approach you could do ”minimal” setup on the >> cape and then (I think someone suggested this in the past) make a bunch of >> EtherCat slaves. Using a microchip LAN9252 coupled with a microcontoller is >> relatively simple to make and somewhat cheap. From the top of my head ill >> say the 9252 requires some 50 components around it and most just resistors >> and capacitors. The EtherCat slave license ”comes with” the LAN9252 so no >> issues >> >> If you pair the slave controller with a popular mcu I think the community >> could do a lot in the EtherCat slave world. >> >> Just my 2 cents. >> >> tiistai 9. kesäkuuta 2020 Stephen Bell <[email protected]> kirjoitti: >>> Agreed on the massive requirements disparity. In my view, given how >>> saturated the market is for stepper-motor based control boards >>> (particularly the Duet 3, which can be controlled by a BBB/RPi) I'd prefer >>> a more Break-out-Board style cape to make industrial-level control more >>> accessible. >>> >>> My ideal cape would have dual etherCAT RJ45 ports, an RS422 or 485 header >>> with voltage selection for PLC/spindle vfd control, UART headers, dual CAN >>> headers and a small array of optoisloators for the other GPIO. Biggest >>> problem for this is the ethercat license, which is somewhat of a pain... >>> >>> I also prefer the web-based GUIs locally hosted on the device, which can be >>> accessed across the network and use less resources than a driven display >>> and a native GUI, so I'd prefer a cape NOT be limited by a desire to have a >>> screen/monitor from the BBB. >>> >>> just my 2C >>> >>>> On Sunday, June 7, 2020 at 12:46:01 AM UTC-4, Malte Schmidt wrote: >>>> I think the issue is always that the requirements with these machines are >>>> very different and that you never quite get what is needed. >>>> When I build the cape I use on my lathe I sort of used a modular design. I >>>> based this on a prototype cape and used those small optocoupler and level >>>> shift modules that you get from China for the maker scene. It looks quite >>>> like a hack but you might see the three opto modules in the back and the >>>> two level shifters here: >>>> https://forum.zerspanungsbude.net/download/file.php?id=188366&mode=view >>>> There is an external pwm-> 0-10V module as well (not shown) for spindle >>>> control >>>> >>>> I always thought about making this nicer. I would have done it this way: >>>> A cape that: >>>> - Make PRU and GPIO Pins available in sets of 4? pins on standardized PIN >>>> headers + power. >>>> - Makes the terminals for connecting the cables available >>>> >>>> PLUS >>>> >>>> Small modules for level shift, opto isolation , spindle control (as >>>> desired). These would use the standardized connectors on the cape. >>>> For this I would actually rely on stuff that is already available (if so). >>>> >>> >>> -- >>> website: http://www.machinekit.io blog: http://blog.machinekit.io github: >>> https://github.com/machinekit >>> --- >>> You received this message because you are subscribed to the Google Groups >>> "Machinekit" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to [email protected]. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/machinekit/4e75a7ba-b13f-4579-a7f1-09211ff4cbd7o%40googlegroups.com. > > -- > website: http://www.machinekit.io blog: http://blog.machinekit.io github: > https://github.com/machinekit > --- > You received this message because you are subscribed to the Google Groups > "Machinekit" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/machinekit/61c7c2b7-e1bb-4c2c-8556-355bf16645b2o%40googlegroups.com. -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. 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