(1) Dual terminal bus. The standard dual terminal bus network topology is connected to a 120Ω terminal resistor at both ends of the bus, and the total bus resistance is 60Ω. This topology is the most commonly used bus topology in elevator because of its simple connection, good reliability and long transmission distance.
< br >
(2) Single terminal bus. The simplest way to match the CAN bus is to attach a 60Ω terminal resistor to the bus. In this topology, the bus resistance is 60Ω and the impedance is matched. However, in this topology, many nodes are actually not on the bus but on the feeder, its transmission distance is limited, and the bus length of this topology is only 50% of the bus length of the standard double-terminal bus connection.