JUMO mTRON T Manual page 15

2.2.1 Terminating resistors
The internal terminating resistors for the Com1 and Com2 interfaces are only relevant for
RS422/485.
The terminating resistors are deactivated by default. To activate them, DIP switches 1 to 4 for
the relevant interface must be pushed upward using a suitable tool such as a ballpoint pen (ON
position).
The following figure shows the position of the DIP switches when the terminating resistors are
activated.
NOTE!
To ensure fault-free operation, terminating resistors are required at the start and end of an
RS422/485 transmission path.
Internal terminating resistors
+5 V
332 ?
1
120 ?
2
332 ?
GND
2 Connecting interfaces
ON
1 2 3 4
+5 V
332 ?
3
120 ?
8
332 ?
GND
4
3
9
4
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