Re: can network establishing -- Can bit timing

Thanks Bertil,

For this nice calculator. But i need to estimate exact propagation segment
delay.

1> But my question is related to estimating the length of the cable to find
*exact propagation delay*. Theoretically length of the cable will be : drop
down length(combined for all nodes) + actual length

2> Mostly delay will also because of drop down connectors & also
trans-receivers .

3> So when estimating total length of network then it will be :
drop down length(combined for all nodes) + actual length  ?

4> Also how much maximum can be drop down length(combined for all nodes)  ?

Any suggestion..!!



On Fri, Oct 18, 2013 at 11:32 AM, bertil bäck <[email protected]> wrote:

> 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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