Installation and Wiring 
 
FPΣ User's Manual 
94 
6.7.1 Transmission Cables 
Please use the following cables for systems using RS485 type communication cassettes. 
Conductor  Insulator 
Type 
Size 
[mm
2
] 
Resistance (at 
20°C) [Ω/km]  
Material 
Thickness 
[mm] 
Cable 
diameter 
[mm] 
≥1.25
 
(AWG16) 
≤16.8  ≤0.5  ≈8.5 
Shielded twisted pair 
1
2
3
4
 
≥0.5 
(AWG20) 
≤33.4 
Polyethylene 
≤0.5  ≈7.8 
VCTF 
1
2
3
 
≥0.75 
(AWG18) 
≤25.1 
Polychlorinated 
biphenyl 
≤0.6  ≈6.6 
 
1
 
Cover 
2
 
Insulator 
3
 
Conductor 
4
 
Shield 
 
NOTE
 
•  Only use shielded twisted pair cables. 
•  Only use one type of transmission cable. Do not mix more than one type. 
•  Twisted pair cables are recommended in noisy environments. 
•  When using shielded cable with crossover wiring for the RS485 
transmission line, ground one end. 
•  If two wires are connected to the plus and minus terminals of the RS485 
port of FPG-COM4, use wires of the same cross-sectional area (0.5–
0.75mm
2
).