Controller Area Network (CAN)
The CAN Basics Training Course provides a practical approach to understanding how CAN works. By giving real world examples, common practices, and an in-depth look at DBC files, Bryan Hennessy gives a real-world walkthrough of CAN.
Presentation by Bryan Hennessy. Recorded as part of a ‘live’ training session in January 2019.
Bryan Hennessy: [00:00:02] So, Controller Area Network, that’s what CAN stands for, and that’s the first lesson. I’ll start out with a few slides as to where CAN is used and what industries and applications it fits. So it’s used in many places. I mentioned that NMEA 2000, which was my exposure, first exposure to CAN, which is actually a pretty small segment of the overall CAN industry, very small. NMEA 2000 was a follow-on to an old standard called NMEA 0183, which was a serial bus RS-422 standard. CAN was used for NMEA 2000 and supposed to be released in 2000 but it wasn’t, it was about 2003 or ‘04 before it really got prevalent out there.
Heavily used in vehicles, automated vehicles I have here, but vehicles in general. EC use, electronic control units in vehicles is probably more CAN out there in vehicles than anywhere else. [00:01:02] Industrial automation, it’s very large, mostly with the protocol CANopen. We’re actually just starting to understand more of how large that is and opportunities there. Very much a medical equipment. We have a lot of CAN customers doing medicals. I hope some of you do as well. I got vehicle engines and controls J1939 and others, which Alex and I are familiar with. So, aerospace, robotics is really big for CAN. Then I just threw this one in. Anywhere where a machine is talking to a machine, it’s likely it’s using CAN for that communication because that’s what it’s really suited for. When I say a machine, I mean an electronic sensor or a temperature sensor. Any time you see the word smart sensor, it’s probably CAN because that’s what the smart is indicating. It’s got a processor in it, it’s probably using digital communications via CAN. So as opposed to a [00:02:02] dumb sensor or an analog sensor which has an analog resistance that changes with whatever factor it’s measuring.
Some examples. Getting the most prevalent. Probably the ECU in the upper left-hand corner. The Kvaser Memorator two channel in the upper right-hand corner. Had to throw that one in. Some other sensors, a couple of these from the marine industry where I used to work, rudder angle indicator. It’s getting rudder angle off a CAN bus. This would be a GPS compass. These are pretty neat. They operate via CAN and they have two GPS signals and two GPS antennas in there. GPS is so darn accurate when you’re that close to each other that that by doing calculations on where those two antennas are this far apart, that can determine very exactly what your hiding is. So they call that a GPS compass. Motors, stepper motors are CAN controlled a lot, smart motors. This would be a wind temperature sensor where the GPS and a bunch of other [00:03:02] things built into it. So this is an overall, again in the marine industry hooks up via CAN.
So here we have some actual applications, things that CAN and some of those components in the previous slide may actually work in. The PACCAR truck, which I worked on extensively when I was with them. A lot of different heavy equipment uses CAN. Lifts and things like that that you see around are big users of CAN. The automobile, of course, is where it started and mostly used. I found a little picture of an automated lawn mower up there. They use quite a bit of CAN. The last one, like Sylvia has pointed out, that it’s used for actual control, surface controls and some high-speed fighters jets as well. So it’s very reliable and able to be used in pretty serious applications like those.