Tyco 4100U-S1 - Manual (Page 86)

5-18
This section describes how the IDNet Channel on the SPS connects to addressable
devices/detectors.
The guidelines governing IDNet wiring guidelines are covered in Chapter 6, IDNet
Installation.
Up to 250 IDNet initiating devices are supported on the SPS IDNet channel. The SPS
supports both Class A (loop) and Class B (string) wiring. Class A wiring is mandatory for
connection to more than 40 devices.
Class A wiring allows IDNet appliances to continue to communicate with the SPS even in
the event of an open circuit somewhere in the loop. Class A wiring requires that two
wires are routed from the SPS to each IDNet appliance, and then back again to the SPS.
Class B wiring allows “T” tapping, and therefore requires less wiring distance per
installation than Class A.
Note that IDNet wiring does not require end-of-line resistors, because each IDNet
appliance communicates directly to the SPS.
Ferrite beads are required on the SPS IDNet cables (refer Figure 5.1). Refer to
Chapter 6 IDNet Installation for the guidelines governing IDNet wiring.
Continued on next page
SPS IDNet Wiring
Overview
IDNet Wiring
Guidelines