mild disclaimer: I don’t really know that much about EtherCAT compared to people I’ve met, I’m just trying to explain as best as I can and play devil’s advocate for it in FRC.
I love communication protocols. In fact, it’s my favorite chapter in Art of Electronics by Horowitz and Hill.
After interning at a local company that works in surgical robotics for the past two summers, I’ve begun to discover the true power of different protocols. Specifically, I’ve discovered the beauty of EtherCAT.
EtherCAT has some stupid crazy advantages:
- 100 Mb/s vs the 1Mb/s that CAN bus has. (Vision through EtherCAT anyone?)
- Based of the Ethernet Physical Standard, so you can literally just use CAT5/6/7 patch cables (or make your own!)
- CANopen over EtherCAT means that you can literally run CAN packets through EtherCAT.
- In my testing, STUPID fast. (I measured 73ms per loop cycle with CANopen vs 5ms with EtherCAT)
- normal NICs can be used. So, in theory, you could just use the Ethernet jack on the RoboRIO.
- Ability to use any topology you want.
My favorite part about EtherCAT by far is how it was initially explained to me. When I first learned about it, I was told that I can think of it as “A big data table that gets filled with data and updated by different devices on the chain.” I instantly though, “It’s just networktables on steroids.” It is, in fact, just networktables on steroids.
Anyways, that’s my rambling. Anyone see that weird movie about the german scientist in a wheelchair that proposes that we live in mines after some government nuclear blunder?