Installation and Connection
There are two different versions of the RS485 interface. By means of the
wiring diagram on the top of your device, you have to find out which
version is built in your device (Type1 or Type2).
Ensure the correct tightening torques.
RS485 – Type 2 (see wiring diagram)
Electro-mechanical assignment Type 2 (see wiring diagram)
The Modbus
®
/ IEC 60870-5-103 connection cable must be shielded. The
shielding has to be fixed at the screw which is marked with the ground
symbol at the rear side of the device.
The communication is Halfduplex.
57
MRU4
DOK-HB-MRU4-2E
1
X
10
3
2
3
4
5
6
P
N
+5V
GND
56
0
Ω
56
0
Ω
120
Ω
Protective Relay
H
F
S
hi
el
d
6
4 5
3
2
1
R1
R2
R1
+5V
GND
R1 = 560
Ω
R2 = 120
Ω
P
N
Protective Relay
H
F
S
hi
el
d
