Rs485 Cabling; Current Loop (20 Ma) Cabling; Fig. 7-6: Rs485 Cabling; Fig. 7-7: Active Transmission/Active Reception - Addi-Data ADDICOM APCI-7800 Technical Description

APCI-7800

7.3.3 RS485 cabling

7.3.4 Current loop (20 mA) cabling

Active / passive : When a transmitter and a receiver communicate, one of
them has to supply the necessary current. If the transmitter supplies the
current, it is active. The receiver is passive. In reverse, if the receiver
supplies the current, it is active.

Fig. 7-7: Active transmission/active reception

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Fig. 7-6: RS485 cabling

Connecting the peripheral