CAN PHY drivers

The board have 2 CAN-PHY drivers: MCP2551 and TJA1055. In application using only one of it.

MCP2551 - the hi-speed CAN bus physical driver (up to 1MBit/s speed, in applications usually 500KBit/s). It used in endine CAN bus and diagnstic CAN bus.

TJA1055 - the lo-speed CAN bus physical driver (up to 125kBit/s). It usually user in comfort CAN bus.

Using hi-speed CAN driver MCP2551

Using fault-tolerance CAN driver TJA1055

Terminal resistor

Terminal resistor (R9) using only if you sure that it needed. In car, CAN-bus always have terminals in some ECU-blocks, and R9 not required. If you test some ECU "on table", the R9 may be need.