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Unread 16-01-2015, 21:30
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FRC #0832
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Re: Using CAN in a star configuration

Quote:
Originally Posted by Thad House View Post
I know you would need termination resistors on each line
Quote:
Originally Posted by Kevin Sevcik View Post
First off, no, you don't need or want more than 2 termination resistors. If you add more resistors, you're going to drop the total resistance between the lines, which will cause problems with signal levels.
The FRC CAN implementation is 1 Mb/s class C, which is very finicky about terminations and stub lengths. You WILL get poorer communications on CAN if you use a star topology without proper terminations, up to and including NO communications.

Go ahead and try it - don't take my word for it - but be prepared to evaluate performance carefully (I suggest a CANalyzer/similar or perhaps an Oscilloscope) and return to daisy-chain if your results are not satisfactory.

It would be a very bad idea to not properly evaluate performance before going to competition. This is not a place to take an unknown risk.
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