Appendix Crs-485 Communication Network - Emerson Rosemount 975MR Reference Manual

Reference Manual
00809-0100-4975
C RS-485 communication network
By using the RS-485 network capability of the detector and additional software, you can
connect up to 32 detectors in an addressable system with four (4) 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 (4) wires. When
using the RS-485 network, you can read each detector status (Fault, Warning, and Alarm)
and to initiate a built-in test to each detector individually.
For more details, consult Rosemount.
Figure C-1: RS-485 Networking
Rosemount 975MR
RS-485 communication network
August 2019
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