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MSR128LUS/MSR128LUV USERS MANUAL EM-7375 Rev.2
2.2.2
ETHERNET MODBUS TCP/IP
Figure 2.2.1a shows a system configuration example via Ethernet using Model 72EM(2)-M4 Ethernet/RS-485 Com-
munication Adaptor. Only one (1) 72EM(2)-M4 can be connected to one PC.
If the 72EM(2)-M4 is directly connected to the PC (Not via a switch/hub), use a ‘cross’ type Ethernet cable.
Figure 2.2.2a: System configuration example, Modbus TCP/IP.
Detail of Modbus wire configuration is as shown in Figure 2.2.2b.
Figure 2.2.2b: Modbus wiring detail with the 72EM(2)-M4.
RS-485 (Modbus RTU)
Multi Power Monitor
(model: 53U)
AX
IN
AX
IN
AX
IN
Ethernet
Communication Adaptor
(model: 72EM-M4 or 72EM2-M4)
ETHERNET
RUN
SEND
FIELD
CNFG
Max. 31 nodes
72EM-M4
72EM2-M4
T1
T2
T3
T4
53U
T1
T2
T3
T4
53U
CONNECTOR
Ethernet
RS-485
*
1
*
1. Internal terminating resistor is used when the device is at the end of a transmission line.
*
2. Install shield cables to all sections and ground them at single point.
*
3. When the 72EM(2) unit is located at an end of transmission line via twisted-pair cable (= when there is no cross wiring),
close across the terminal 2 – 11 with the terminating resistor attached to the product.
Remove the resistor from those located between the end points.
*
2
*
3
FG
RS-485
2
+
–
11
1