4-5
Interfaces of the Device
4.1.2.2 Termination
For point-to-point connections, always activate the termination. For multipoint con-
nections, only activate the termination at the cable end.
Figure 4-4 Block diagram termination RS422 / RS485
Legend for table:
I = Switch ON
- = Switch OFF
Table 4-5 Resistor values - termination RS422 / RS485
Designation Value
R1, R3 510 Ohm
R2 150 Ohm
R4 120 Ohm
The switch positions for ON or OFF are printed onto the termination switch. Only the
specified switch positions are allowed.
Table 4-6 Termination switch
S1 S2 S3 S4 Function
Transmit-
ter
Receiver
I I I I Termination is ON
– – – – Termination is OFF
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