Emerson Rosemount 935 Quick Start Manual page 34

Quick Start Guide
A.1 RS-485 communication network
Using the RS-485 network capability of the Rosemount 935 detector and
additional software, it is possible to connect up to 32 detectors in an
addressable system with four wires only (two for power and two for
communication).
Using repeaters, the number of detectors can be much larger (32 detectors
for each repeater) up to 247 on the same four wires. When using the RS-485
network, it is possible to read the detector status (Fault, Warning, and
Alarm).
For more details, consult Emerson.
Figure A-6: RS-485 Networking for Wiring Option 3
A. Controller
B. First detector
C. Last detector
D. Power supply
E. RS-485 computer port
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April 2021
Emerson.com/Rosemount