The line ends of the bus segment must be equipped with bus terminating resistors. Normally, these resistors are integrated in the interface connectors.
1
Term. P
2
RxD/TxD-P
3
RxD/TxD-N
4
Term. N
A
Master at the bus line end, pull-up resistor and pull-down resistor activated, bus terminating resistor 120 Ω
B
Slave within the bus line
C
Slave at the bus line end, bus terminating resistor 120 Ω