Re: can network establishing -- Can bit timing

Hi,
have a look here:
http://www.bittiming.can-wiki.info/

For Freescale msCAN (HCS12) use SJA1000 

Br,
Bertil Bäck
R&D Manager, Hardware
TK Engineering


----- Original Message -----
From: "Eric clawson" <[email protected]>
To: [email protected]
Sent: Thursday, October 17, 2013 8:18:40 PM
Subject: [CANLIST] can network establishing -- Can bit timing



Hi, 

I am working on a CAN network where i have 20 nodes attached to my network. 

Speed = 125 Kbps 
Clock = 8 MHZ (I can increase it further if required) 
Nodes = 20 
Cable = 120 ohm characteristics impedance. 
Drop Length per node = 2 meter 
Total length of cable network = 80 Meter 

1> Now how can i set the Bit timing for my CAN network so that with this topology it works at 87.5% sample point ? 
One experience person told me at 125 KBPS we can cover :-- 

    * 500m length total. 
    * Double the length of drop down cable. 
    * Maximum length of drop should be 120M 
    * Also for every connector consider 6 meter loss in length. 


2> Please suggest is above calculation right? 
3> If not then what eactly should i keep the value of propagaton segment of my network? 
4> Also what value to be kept for phase segment 1 & 2 ? 

I am also refering an1798.pdf for it. But i need some to share his experience in setting CAN network . 

//Eric
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