Serial Decoding - CAN High

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Lukasz Matuszak
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Serial Decoding - CAN High

Post by Lukasz Matuszak »

Hi guys, is there any way I can see each data byte separate on the graph? What I mean is that I am interested in seeing data byte "1F" on the graph. Can PicoScope6 calculate or show me with rulers that specific data byte I'm looking for on the graph? Please see I attached photo with it. Thanks, Lukasz.
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CAN-High.psdata
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PicoScope 6_CAN_High.jpg

Hitesh

Re: Serial Decoding - CAN High

Post by Hitesh »

Hi Lukasz,

It should be possible to decode data between rulers but unfortunately a bug has been discovered in relation to this feature.

I have added your data file to the existing bug report for our Development Team to investigate.

An update can be provided here if you wish.

Regards,

Lukasz Matuszak
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Re: Serial Decoding - CAN High

Post by Lukasz Matuszak »

Hello Hitesh,

That will be great if any news will be updated into this post :)

Also I was working on that graph since I post a topic. What I have found out is, that you can calculate yourself the CAN frame format, which is on wikipedia (http://en.wikipedia.org/wiki/CAN_bus) "Base Frame Format" Heading, half way threw the page. So I started calculate/measuring and everything seems to be right till I hit my Data Bytes.

Example: DB1: -From the Data Bytes clearly you can see DB1 is 0 where on the graph by my calculation is 1.

I just want to share what I have found out that could help ye guys maybe. Thanks for answer Hitesh.

Regards,
Lukasz
Last edited by Lukasz Matuszak on Thu Oct 09, 2014 3:02 pm, edited 1 time in total.

Hitesh

Re: Serial Decoding - CAN High

Post by Hitesh »

Hi Lukasz,

Thank you for the image of the manual decode.

I have added this information to the bug report.

I can provide an update in this thread once this has been investigated.

Regards,

Mark_O
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Joined: Fri Oct 03, 2014 5:58 am

Re: Serial Decoding - CAN High

Post by Mark_O »

Lucasz wrote:
So I started calculate/measuring and everything seems to be right till I hit my Data Bytes.
Example: DB1: -From the Data Bytes clearly you can see DB1 is 0 where on the graph by my calculation is 1.
Did you take into account bit-stuffing? I see lots of contiguous 0's in your data stream.

Lukasz Matuszak
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Posts: 0
Joined: Thu Sep 11, 2014 8:47 am

Re: Serial Decoding - CAN High

Post by Lukasz Matuszak »

Mark_O wrote:Lucasz wrote:
So I started calculate/measuring and everything seems to be right till I hit my Data Bytes.
Example: DB1: -From the Data Bytes clearly you can see DB1 is 0 where on the graph by my calculation is 1.
Did you take into account bit-stuffing? I see lots of contiguous 0's in your data stream.
Hi Mark_O

Your right there is bit stuffing. "In CAN frames, a bit of opposite polarity is inserted after five consecutive bits of the same polarity". I was doing this so fast that after posting my reply I was reading it again and I have to say I made mistake. Please see I attached photo in which I can tell where "1F" Data is.
Attachments
Data Byte 1F.jpg

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