Engineering Documentation

Table Of Contents
Chapter 2 Network Electrical Systems
RS-485 ALN (P2/P3) and FLN (P1) Trunk Communications Wiring
125
-3002
51 | 231
RS-485 2-Wire Network Devices
To minimize risk and reduce installed costs, use only the network devices listed in the
following table on RS-485 ALN and FLN trunks. The following table lists the power
source requirements for each network device.
See each product section in this manual for specific device power source
requirements.
Power Source Requirements for 2-wire RS-485 devices.
Product Input Voltage Line Frequency Maximum Power
HSTIE 115/230 Vac 50/60 Hz 6 VA
Trunk Interface II 115/230 Vac 50/60 Hz 6 VA
Fiber Optic Trunk Interface 115/230 Vac 50/60 Hz 6 VA
Fiber Optic Hub 115/230 Vac 50/60 Hz 10 VA
High Speed Trunk Interface (HSTIE)
The High Speed Trunk Isolator/Extender (HSTIE) is used to protect, isolate, extend
(re-time) an RS-485 ALN or FLN trunk. Only the HSTIE can extend the maximum wire
length of a trunk segment. Other devices such as Trunk Interfaces with leased line
modems or fiber optics do not increase the maximum wire length of a trunk segment.
Fig. 26: Connections to HSTIE.