CNT-SVX05A-EN
25
Communications
Wire characteristics
UCM communication-link wiring must be low capacitance, 18-gauge, shielded,
twisted pair with stranded, tinned-copper conductors. For daisy chain
configurations, limit the wire run length to 5,000 ft (1524 m). Trunk and branch
configurations are significantly shorter (see Figure 3). Comm5 wire length
limitations can be extended through the use of a link repeater.
Wire capacitance (measured in picofarads/foot [pF/ft] or picofarads/meter
[pF/m]) between conductors must be 23+/-2 pF/ft (72+/-6 pF/m).
Link configuration and termination
Communication-link wiring must use one of the following configurations:
• Daisy chain configuration (preferred), shown in Figure 3
• Trunk and branch configuration, shown in Figure 4
Figure 3 — Daisy chain configuration for communication-link wiring (preferred
configuration)
• Limit total wire length to 5,000 ft (1,524 m). (Comm5 wire length limitations
can be extended through the use of a link repeater)
• See the following section on
Termination resistance placement for
Comm5 links
