Installation and Connection
Communication Interfaces
Modbus
®
RTU / IEC 60870-5-103 via Terminals
Make sure that the tightening torque is 0.22-0.45 Nm [2-4 In-lb].
Terminal Marking X103
for the device:
MRA4
Electro-mechanical assignment for device: MRA4
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.-
EN MRU4 10/09
Page 33
6
4 5
3
2
1
R1
R2
R1
+5V
GND
R1 = 560
Ω
R2 = 120
Ω
P
N
P
*
N
*
Protective Relay
1
X
10
3
2
3
4
5
6
P
N
P
*
N
*
+5V
GND
560
Ω
560
Ω
120
Ω
Protective Relay
