Huvitz CDR-3100 - Problem in Communication; Basic Things in CAN (Controller Area Network); Some Direct Causes of Failure and Its Results

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4.3 Problem in communication
4.3.1 Basic things in CAN (Controller Area Network)
① CAN use only 2 lines (wires).
② The length of main line can reach upto 100m.
③ The length of sub lines’ is limited to 3m.
④ Terminator must be placed at the ends of main line.
⑤ If there is only one system on the CAN, only one terminator is needed.
4.3.2 Some direct causes of failure and it’s results.
▣ Grades of failure.
A. All the devices on CAN do not work.
B. Only one device which has the problem doesn’t work.
◈ Basic 5 cases of failure and it’s results
Terminator is abs① ent. => A
CANH and CANL is short circuited.② => A
CANH and/or CANL is short circuited to GND.③ => A
CANH and/or CANL is opened. ④ => B
CANH and CANL is swapped.⑤ => B
Note)
1. CAN board failure commonly belongs to case ④ but sometimes it can
Refractor Body
Terminator
CANH
CANL
Terminator
Main line
Sub line
PC