I do wish that Ethercat was truly open source from the ground up. Beckhoff holds all the copyrights, and has an annoying association that holds all the docs. Membership is free, but a hassle. I am jumping through the hoops to join, but haven't finished yet. A real open source vhdl module for FPGA's would be really nice, to avoid single source chip risks. There are a couple of projects on Github, but both are empty of actual source code.
What I like about Ethercat is it is truly real-time, whereas Ethernet/IP does not guarantee timing. The two-port daisy chain approach of Ethercat is also very handy. Actually, you made another suggestion that has me thinking again. The Mesa LBP16 protocol over ethernet is typically just used to connect a host pc to a single fpga card, which has i/o and possibly sserial links to additional i/o. The sserial i/o has some limitations on speed and is best suited to pendants and coolant or tool changer type use. I'm wondering if a reasonably fast pc with GigE and a GigE switch could have a number of LBP16 devices running full speed, one device per port on the switch. Hostmot2 already supports multiple devices, although I've never tried using more than one per pc. -- Ralph ________________________________________ From: John Figie [zephyr9...@gmail.com] Sent: Tuesday, February 22, 2022 4:40 PM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] FW: [MachCNC] Mach4 teach/record CAUTION: This email originated from outside the Walla Walla University email system. Actually What I described is not exactly Ethercat but more similar to Ethernet/IP with CIP Motion. Ethercat is not standard Ethernet and that is why the slave requres the mictochip interface device. But if open source master and slave implementations are available maybe that would be a good possibility. Since an Ethercat slave does not use standard ethernet I believe that the master tunnels other protocols through the eterncat networks, although I think in theory both protocols might be able to exist since Ethercat is its own ethertype so that packets can be separated form ethernet protocols. Anyway, for a dedicated network of just I/O Ethercat works very well. On the othehand the problem with using CIP Motion is that you need to belong to ODVA and pay a fee to get the specification so although they claim it is open it really doesn't seem so and I am not sure if it could be used in an open system because then the specifications would also be public. It would be nice if there were a simple and free open protocol and if it were based on standard ethernet then it could be long lasting and would be extensible to faster ethernet speeds and IP-6 if needed. John Figie On Tue, Feb 22, 2022 at 5:35 PM Ralph Stirling < ralph.stirl...@wallawalla.edu> wrote: > I think you have just described Ethercat. There are open source Ethercat > master and slave implementations (soem and soes). The slave requires a > Microchip interface device (LAN9252). I would like ethercat interface to > steppers of various sizes, and may work on that this summer. > > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-users&data=04%7C01%7Cralph.stirling%40wallawalla.edu%7Ceef0e9f1f5b64761b5f008d9f6652388%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C0%7C637811736531950502%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=MhUvzgVLEheCyn04c%2BQ9qAQ61O6NBdCMWYa%2BLx%2BBuag%3D&reserved=0 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
