Re: CAN bit timing, Seg2 =1Tq

Bertil Bäck <[email protected]> Thu, 1 Sep 2016 15:06:12 +0300 (EEST)
Newsgroups gmane.comp.hardware.bus.can
Message-ID <[email protected]>
CANopen also specifies 800kbps as speed. If you don't want to drop down to 500kbps. 

Depending on what you do you can also run other speeds. 

Br, 
Bertil 

----- Original Message -----

From: "Amitai Broyde" <[email protected]> 
To: [email protected] 
Sent: Saturday, July 16, 2016 5:01:57 PM 
Subject: Re: [CANLIST] CAN bit timing, Seg2 =1Tq 




Got it, 

Thanks, 



ab 



‫בתאריך שבת, 16 ביולי 2016 ב-15:05 מאת ‪Bram Kerkhof‬‏ <‪ [email protected] ‬‏>:‬ 





The first thing I usually do in these kinds of situation is rethink whether I am: 
A) Using the right technology 
B) Using the technology right 

The big advantages of CAN for me are that it is cheap, simple and reliable as long as you keep away from the bleeding edge (it’s called ‘bleeding’ for a reason ;-). 
When pushing the limits like this, you’ll end up with a system that’s either cheap and simple or reliable, which is probably not what you want. 

Keep in mind that impedance is everything at this point, and that you don’t only have to consider the backbone cable, but also all the connections in between. What works for 35m between two nodes, may not work over the same distance with multiple nodes on the bus. 

Do you really need 1 mbits? Chances are you can simply drop down to 500kbits without too much work. 
If throughput is an issue, consider splitting the network with a gateway. If timing determinability is an issue, consider a time-sensitive protocol implementation (like TTCAN) and a lower bandwidth. 

Or use something else entirely. 

Cheers, 
Bram 

From: [email protected] [mailto: [email protected] ] On Behalf Of Amitai Broyde 
Sent: vrijdag 15 juli 2016 9:30 
To: [email protected] 
Subject: [CANLIST] CAN bit timing, Seg2 =1Tq 





Hi, 

I am using 1Mbps CAN network based on Cores running at 8MHz. I would like to extend the bus length by setting sampling point 125ns before end of bit time. Current bit sampling time is 250ns before end of bit time. 

Will it work? 



Regards, 

ab