Mitsubishi QD51 - RS-422;485 Cable Specifications

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MELSEC-Q
3 SPECIFICATIONS
3.3.2 RS-422/485 cable specifications
The following shows the RS-422/485 cable specifications.
(1) Use an RS-422/485 cable (cable connected to the QD51(-R24) terminal block),
which satisfies the following specifications, with a length of 1200 m or less.
(2) Also, when connecting multiple devices at 1:n, n:1, or m:n, keep the total cable
length within 1200 m.
(3) The RS-422/485 cable specifications are shown below.
Item Description
Cable Type Shielded Cable
Number of Pairs 3
Conductor Resistance (20°C) 88.0 Ω / km or less
Insulation Resistance 10,000 MΩ - km or greater
Voltage Resistance 500 V DC 1 minute
Electrostatic Capacity (1 KHz) Average 60 nF/km or less
Characteristic Impedance (100 KHz) 110 +/- 10Ω
Recommended conductor size 0.2 mm
2
to 0.75 mm
2
(Recommended Cables)
SPEV (SB) – MPC –0.2
3P : (Manufactured by Mitsubishi Electric Wire Co.
Ltd.)
SPEV (SB) – 0.2
3P : (Manufactured by Mitsubishi Electric Wire Co.
Ltd.)
The electrical characteristics of the recommended cables SPEV (SB) -MPC-
0.2
3P and SPEV (SB) -0.2 3P are equivalent, but they differ somewhat
in their external dimensions and internal wire colors.