Emerson Rosemount 975MR, Reference Manual

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Table 1-9: Available Output Types
Output type Version Detector status
Alarm relay 975MR- output configurations
1AXXXXX, 1RXXXXX, and
2RXXXXX The relay is N.O.
975MR - output configurations
2AXXXXX and 3AXXXXX The relay is N.O. and N.C.
Auxiliary relay 975MR - output configurations
1AXXXXX, 2AXXXXX, and
1RXXXXX The relay is N.O.
Fault relay 975MR - output configurations
1AXXXXX, 2AXXXXX, and
1RXXXXX The relay is N.C. energized.
975MR - output configurations
3AXXXXX and 2RXXXXX The relay is N.O. energized.
0-20 mA current output 975MR - output configuration
1AXXXXX Sink with the HART protocol
(can be changed to Source - see
Figure B-3 , Figure B-4 , and
Figure B-5 ).
975MR - output configurations
2AXXXXX and 3AXXXXX Source with the HART protocol
RS-485 All versions Modbus protocol
1.5.6 Detector status
The possible detector function statuses are listed in the table below. Use HART
®
or
Modbus
®
to see a more detailed fault analysis.
Table 1-10: Detector Statuses
Status Description
Normal Normal operation.
BIT Built-in test being performed.
Warning Fire detected - changed to
Warning
(pre-alarm state).
Alarm Fire detected - changed to
Fire Alarm
state.
Latched alarm (optional) The alarm outputs remain latched on following detection of a fire
that has already been extinguished.
BIT fault A fault is detected during built-in test sequence or other electric
failure. The detector will continue to detect for fire.
Fault A fault is detected when the power supply is too low or due to a
software fault or electrical failure. The detector will
not detect fire
in this condition.
In each state, the detector activates different outputs, as specified in Table 1-11 .
Introduction Reference Manual
August 2019 00809-0100-4975
20 Emerson.com/Rosemount