Connection Terminals Of The Serial Interface And Microswitch S4; (Bus Terminating Resistor); Two-Wire Rs485 Connection - Eaton M-Max Series User Manual

Serial Interface A-B
The following figure shows the connections of the serial interface and the position of the
micro-switch for the bus termination resistor.

Connection Terminals of the Serial Interface and Microswitch S4

(Bus Terminating Resistor)

The two control signal terminals A and B enable the connection of a shielded RS485
twisted-pair cable.
The bus terminating resistor required at the end of a data cable is integrated in the frequency
inverter and can be connected via microswitch S4.
The network cable must have a bus termination resistor (120 ohms) connected at each
physical end to prevent reflections and the resulting transmission faults.

Two-Wire RS485 Connection

(Slave = M-Max Frequency Inverter)
120 ohms
Slave
S4
A
B
RS485
Modbus (RTU)
The parameter definition of the serial interface is described in "Serial Interface
(Modbus RTU)" on Page 131.
AI2 GND DO– DI4 DI5 DI6 AO DO+
4 5 13 14 15 16 18 20
1 2 3 6
+10V AI1 GND 24V DI-C DI1 DI2 DI3
Master
A
B
M-Max Series Adjustable Frequency Drive MN04020003E—October 2013 www.eaton.com
R13 R14 – R24
22 23 26
8 9
7 10 25 24
A B R21 R22
S4 = RS485 (–)
Installation
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