And just to say, I am updating my motor drivers every 7ms at the moment, try that on RS485.....
what do you imagine would be the issue?
ehehe, I worked on some industrial cutters connected to reels-winding, machines of several tons, as big as a room that make shopping bags for supermarkets, unroll a reel of thin plastic film, cut it, and seal it hot, also making 16 bags in parallel.
I happened to have to design a perimeter Lidar 2D, and a part of the unit that manages both the pneumatic part and the blades array, and then have to interface them with the "computer" that manages the machine, which I have no idea what it is (I couldn't take a peek (1)), but I found EtherCAT, which I also found in avionics, as well as AFDX, in UDP/IP based applications with custom go-back-n algorithms.
They { EtherCAT, AFDX } are both ethernet based, but have been modified to be not only deterministic, but also lightweight, and in the work I have done, the response time was within 5 msec.
I found Tulip chips (ex Digital tecnology), which, in Linux and VxWorks terms, they "
offload the CPU" - written like this in the manuals - by performing lowlevel (LLC) checksums and performing networking operations autonomously, so the CPU, doesn't matter if it's a superscalar PPC460 with 4 cores and 32MByte of L2 cache!!!, rather than a non-superscalar MIPS-I wheelbarrow, with neither cache nor pipeline, the CPU always sees "the network coprocessor" as interrupt-driven and DMA-driven partner.
Similarly, in the world of perimeter security (both civil and military, from avionics to naval), I have seen engineers with 30 years of experience, i.e. people who started working in 1990, developing solutions based on RS485.
They know how to do it because they have been doing it for a long time, and they are solutions that couple the RS485 with ad-hoc intelligent cards that practically do "offload" networking functionalities.
Pretty like Tulips (used in { EtherCAT, AFDX, ... }) and CanBUS.
- - -
So, in my opinion today there is a lot of emphasis on canBUS because it presents itself as a ready-made package, as well as Bosch is a very solid and serious company that offers solid guarantees, while these 90s engineers are close to retirement age, so it would cost more to train new engineers, also considering that it is a rather old technology.
It costs much less, and that's not something to underestimate
![Confused :-//](https://www.eevblog.com/forum/Smileys/default/confused0024.gif)
(1) the security guy was watching me closely, and he was much bigger than me - "
don't touch that panel!!!" - I risked getting slapped several times!
I was abroad on a business, so … somehow I managed to keep my curiosity in my pockets.