3
SPECIFICATIONS
3.3 RS-422/485 Interface Specification
3.3.2 RS-422/485 cable specification
3 - 7
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OVERVIEW
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SYSTEM
CONFIGURATION
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SPECIFICATIONS
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MODBUS(R) STANDARD
FUNCTIONS
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FUNCTION
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PRE-OPERATIONAL
PROCEDURES AND
SETTINGS
7
PARAMETER SETTING
8
UTILITY PACKAGE
(GX Configurator-MB)
3.3.2 RS-422/485 cable specification
This section explains the specifications of RS-422/485 cable.
(1) RS-422/485 cable to be used
The RS-422/485 cable should meet the following specifications and used within
1200m(4592.4ft).
(2) When making a 1:n connection
When connecting to multiple devices (1:n), ensure that the overall distance is within
1200 m(4592.4ft).
(3) RS-422/485 cable specifications
Table3.2 RS-422/485 cable specifications
Item Description
Cable type Shielded cable
Number of pairs 3P
Conductor resistance (20 )
88.0 /km or less
Insulation resistance
10000M -km or more
Dielectric withstand voltage 500VDC, 1 minute
Electrostatic capacitance (1 kHz) 60nF/km or less by an average
Characteristic impedance (100 kHz)
110±10
Recommended conductor size
0.2 mm
2
to 0.75 mm
2