CAN Bus Properties and Troubleshooting
ฝัง
- เผยแพร่เมื่อ 16 พ.ค. 2024
- Additional troubleshooting tips and resources here: support.enovationcontrols.com...
Note: For in-depth detail about the physical layer and termination resistors, we recommend you read Application Report (SLLA270) from Texas Instruments: www.ti.com/lit/an/slla270/slla...
Chapters
00:00 Introduction
00:23 What is a CAN Data Bus?
01:00 Components of a Physical CAN Data Bus
01:44 CAN Bus Topology
02:38 CAN Bus Electrical Characteristics
03:07 Oscilloscope View of CAN Bus
04:35 Measuring a CAN Bus with a Multimeter
06:34 The Importance of Termination Resistors
08:16 Troubleshooting Step 1: Verifying Termination Resistors
10:23 Troubleshooting Step 2: CAN Hi & Low Wired Backwards
11:59 Troubleshooting Step 3: CAN Signal Missing
12:54 Troubleshooting Step 4: CAN Signal Shorted
17:54 Conclusion - วิทยาศาสตร์และเทคโนโลยี
Hats off to Enovation Controls for doing what major OEMs would refuse to do because it would hurt their bottom line in service repairs. This is exceptional customer service!
assumption
It is much easier to understand when you can see the system as a whole. You are a great teacher. This knowledge is worth more then gold.
I'd rather have a couple of oz of gold.
Great video, exceptionally clear for an introduction to CAN bus. Troubleshooting scenarios were great information for just learning the characteristics of the bus connections vs it’s comms.
Best video ever about CAN systems! God bless you!
This is what I have been looking for for years, nobody explained it better than this.
Love it! Clear and condensed troubleshooting guide. Must see for a DIY person.
i studied can troubleshhoting class for a sort of hi tech devices .... your are a SCHOOL yourself .. u helped me much pin point instead of replacing pcbs as trials & error.. all the best
Excellent content, thanks for putting it together in a concise well edited video.
Theory of operation is always useful , troubleshooting techniques are indispensable . Thanks for giving both , and practical points too for using a DMM as the primary analytical aid.
This is the best educational video on CAN bus I've ever seen. Thank you for explaining in such good detail
This is an absolutely fantastic demonstration. Thankyou for spending the time to make this video.
One of the best CAN bus videos I've ever seen.
This is great, nice simple introduction to the CAN system for someone like me with long experience of servicing good old fashioned analogue electronics and old simple classic car electrics. And the signal reflection action is probably a bit like what happens when setting up a CB radio rig where you get too much RF reflected back down the cable when the aerial, or antenna, is not properly tuned. And this system reminds me a bit of the digital control systems for model railways where just one power supply can feed all the track but each train, or locomotive will only respond to it's own control commands sent through the same tracks as they each have their own decoder fitted which are all different and only recognise their own codes. But of course even with the CAN system there will still be the age old problems of intermittent connections often caused by corrosion or vibration over time etc. and in my experience with some more modern vehicles I've found that some wiring connectors are ok until they're unplugged and they sometimes start playing up and go intermittent after they're reconnected so I suppose that can happen with this system too, and some more recent vehicles have far too much stuff crammed into too small a vehicle making some wiring well nigh impossible to get at.
This is an excellent demonstration, thank you! Now I see why they call NMEA 2000 a modified CANbus system. Thank you, sir.
Finally, a video that explains it best. I retired from a rf tech working on radio equipment so have kind of a clue. This is very helpful.
Great video, now I have a better understanding of this system. Thank you!
Excellent tutorial! You explained the CAN bus and trouble shooting so clearly - Thank You!
I kind of understood can bus in automotive field, but this knocked it put of the park. What a great video and explanation for a not so smart guy like me. Thanks!
Thank you so much, mister. You explained and covered this topic properly and answered majority of the anticipated questions.
I must agree! Great video. We see this in all the vehicles we integrate electronics into
This is absolutely fantastic! Short, informative just as it should be.
Thanks for your time and effort making this! It’s appreciated! 👌🏽
Absoluely fantastic informattived thankyou somuch all controlled tress bled all welcomed
That demonstration board is really neat, thank you for posting this.
Great explaination and easy understanding. Spending 18 minutes to watch your video can save many working hours for us. thanks alot!
Thank you, great tutorial on troubleshooting CAN Bus problems.
Nice thorough explanation. Thank you! Great job!
Nice breadboard/posterboard design. Has just the right components! You put a lot of thought into this!
Thanks so much for this. I am actually an automotive technician but the principles of CAN are the same in our industry.
I've had battle with bad connections on our A&B Devicenet system on a rolling mill. I finally found a good spot in the middle of the loop I can break into and hook up my meter. I use a Fluke with a detachable face and I take the meter face with me and go around to the different components on the loop and lightly give each one a tap and watch the resistance to find the culprit. The Profibus is similar and they use a higher value termination resistors. They use plugs with a D-connectors at the nodes that also have a switch in the plug to switch in or out a termination resistor and sometimes the switch can get dirty and cause problems. I hook up the meter and tap the connectors to find the offensive plug. Your troubleshooting example is spot on. Very good indeed. There is still a lot more for me to learn about these systems.
Fluke 233a, good meter. Mine died after 10years. Now I've got a flir dm93. More durable, and can like to your phone.
Super demonstration of the CAN Bus system. I'm electronic automobile master technician and most of the content would apply to car and motorcycle as well.
I'n car, the resistance are included in some device such as ECM and cluster or fuse box.
excellent in terms of the experiment made, verbal communication, content everything
Thanks for your effort to put this video, really very useful information about CAN.
Brilliant video. Clear layout and processes. Well done !
Simply awesome, chased a can bus in a Nissan for weeks because someone cut can-high installing a stereo, wish I had this info then, thank you
This was a great presentation! Much appreciated!
Thank You so much for this video lesson!
The IT is to Empower yourself and the DTT is to Empower others this is how the technology is moving now days its a time for us to empower other
Было бы замечательно, если бы Евгений на своём канале сделал видео в таком же формате! Как я понял, это видео о возможных проблемах с CAN и их обнаружения. Но так, как не владею английским языком, то очень тяжело принять информацию. А у Евгения, как ни у кого другого, получиться донести информацию.
Привет ! Евгений ждём от Вас такого же видео только на русском !!! СПАСИБО !
Женя я переведу тебе,повесь на своем канале,было бы здорово
No better way to explain and to show how CAN BUS works! 👍
Very clear and concise presentation.
The troubleshooting shortcuts and wrong impediance is very good. Thank you
Thank you! Simple and clear demonstration!
Excellent. Very informative & precise.
That was as close to a perfect presentation as I have ever seen. Thanks!
Excellent video, thank you. I have a Marklin Central Station 2 controller unit for my G-Scale model railway which uses a CAN Bus and Gateway to control the trains and various accessories via Decoders, such as points (switches) and signals, model lights, motors, etc. This has really helped me understand how my bus should be setup, and the purpose and use of terminators (snubbers?), and how stubs (track feeders) are used to connect at regular intervals to the centre of electrically isolated sub-sections of railway track, which in so doing also helps to isolate and more easily find bad track connections (caused by weather/corrosion), and reduces bus data reflections. Plus you show how to perform diagnostics on it all. Really VERY useful and well taught. Thanks, Jim
Thank You so much sir for this well explained presentation video. I gained knowledge and understanding on how to check and troubleshoot the CAN Bus.
Excelente trabalho. Congratulations from Brazil.
Awesome video!! Thanks for sharing. One thing you did but didn't mention was when measuring termination resistors you had the power off. If on and communicating this can throw reading off. So make sure power is off for termination resistor measurement.
open and more advanced education .... i would like to thank so much for your amazing explanation.
Boils it down to basic multimeter troubleshooting concepts well. Thank you!
A very well scripted and presented video, kudos.
Great video, very informative and educational well done!
Happy to see video like this in TH-cam ,Thank you
Super informative, the demonstration really clarifies everything, thank you!
So helpful!! Thank you so much!
highly informative. Appreciate the explanation while using the bare minimum tools as well. I already played the process of elimination game to figure out the short to Gnd on CAN bus. but knowing how the CAN voltage responds to specific conditions is helpful AF
Very well explained. Thank you for sharing this video
Let me add my voice to the chorus: Thank you! (My interested is automotive) Not to detract from that, there is one thing I think is "missing" and may be confusing to some students. It would be good to run a third wire below the CAN pair showing ground going to all the units, and to which the CAN signals are referenced. ( in fact power might not be bad to show as each of those devices is connected also to power and ground). The problem is that in conventional circuits (non CAN) a pair of wires (particularly a twisted pair) carries one signal, the voltage in one being in respect to the other. In CAN, each wire caries a signal with respect to ground AND also with respect to the other. One signal being the mirror of the other (with respect to 2.5 volts) . While in trouble shooting one looks at the individual signals, each device actually looks at the differential signal. The reason for all this is that it is a very noise immune topography. Noise that gets into one signal also gets into the other, and thus the difference signal is unaffected by noise. BTW, the reason the signal rides on the 2.5 volt carrier is 1) it is tricky in the electronics to handle signals that approach zero (zero crossing issues), and 2) at low and zero volts, no current is carried. The higher the voltage, the higher the current being pulled into the termination resistors. The higher, the current, the greater the signal is with respect to any inducted noise signal. Inducted noise can create high voltages in a high impedance line, but since inducted noise is of low power potential, it produces relatively little voltage in a low impedance line. Thus CAN architecture uses four tricks to overcome noise 1) low impedance transmission (on the backbone), 2) differential signal pair transmission, 3) A base line offset from zero and 4) twisted pair transmission line (decreases inducted noise in the differential signal) .
Thanks again for you excellent tutorial !
Had a weird problem with Flight Attendant call lights where three non-consecutive rows of call function (lights and chime) were inop which seemed to be related, yet no obvious connection in the system. HOWEVER.....a system self-test illuminates all the lights, yet the individual call button would not illuminate the call light. D.E.U. (Decoder Encoder Unit) did not seem to be the problem......and the plane had to fly before further troubleshooting could be accomplished. If I'm not mistaken I believe the Att call system is a CAN Bus system. The troubleshooting manual addresses failures in consecutive seat rows (a DEU or wiring) but not for separate rows spaced throughout the cabin. How can all the lights be lit during system self test and yet the individual buttons don't activate the call light in certain rows? (Yes, the circuit boards with the push buttons were swapped out. No help.) Any ideas?
Think they are a given, as it's another 2 wire interface. Just like with I2C they will show SDA and SCL, but of course there is ground and power. Again with SWD, it is called Single Wire Debugger but uses 3 wires. I think once used to that common standard, it would perhaps complicate to run the additional wires.
OMG! Great training! can you do a video on bit stuff errors? how about more advanced troubleshooting topics?
This is absolutely perfect! Excellent video, thanks!
Absolute gem. Exactly what I needed to know. Thanks
This was very Helpful ! Thank You for this demonstration.
One of the most concise, well thought out lessons I have seen. Thankyou!
Thanks..one of the best explanation I have come across
Thank you so much for sharing this great video!
A superb well explained video, thank you.
Great video
straight to the point ..good video ..this is a must see video for can bus diagnostics Tech .this is a fundamental Diagnostics steps
Great video! Very informative and taught me a lot about CAN bus!
The Best explanation! Thank you!
Interesting video, thank you, made easier by having the components neatly laid out. My experience of trying to diagnose CAN Bus problems in the real world of a complex car is that are just too many potential failure points, everything is inaccessible and fault finding becomes very difficult.
That exactly why you wouldn't want to buy a flood damaged car
Fantastic explanation - Thankyou !!
Fantastic explanation and very easy to follow!
Thank you sir.. BEST KNOWLEDGE on CAN BUS .
Wow this video is so well built thank you for the refresh
Thanks for explaining it experimentally. 😊
Great content! So helpful. Thanks!
Excellent, I feel like I CAN troubleshoot this now!
Nice troubleshooting. Thanks for putting it here.
i respect your authority sir. you are very knowledgeable
Keep up the good work Dan! You are a God send . . . Thank you!
Thanks for this video! 3 minutes in and my question is answered 😊.
Excellent peace of work
Thanks for this. This just helped me sort thru CAN bus issue in a Fusion. Saved for future reference.
Great demonstration
Such an elaborative video. Thank you so much for this.
Great video, clear and easy to follow
Good explanation. Loved this.
Thanks for the info, it is very useful.
Fantastic explanation. Really appreciated!
Awesome, some great Troubleshooting tips
Good information 👍. Thank you.
Simple and effectively explain thank u very useful
Thank you for such a wonderfull video on Can bus.
Excellent video, very helpful.
Wow that was a great explanation. Thank u for your time explaining this
🙏 thanks for this worthy contribution!
Thanks a lot for the explanation!!
Wow that’s very informative. Thanks a lot
Great explanation.keep it up .
Very informative, thank you
Thankyou for your work
Awesome video. Clear and to the point
Thanks for the refresher.....