Emerson Rosemount 975 - Initial Setup; Continuous Feature Test; Response to Fault Indication; Built-in Test (BIT)

4 Initial setup
4.1 Continuous feature test
The detector is supplied with default settings, including a continuous feature test.
To change these settings, refer to the Rosemount 975 Flame Detectors Modbus
®
Manager
Manual.
During normal operation, the detector tests itself continuously and indicates a fault if a
failure is found. This type of test complies with SIL-2 requirements.
The detector continuously tests:
• Input voltage level
• All internal regulator voltage level
• Voltage level status of sensor and sensor circuitry for noise or disconnection in the
electronic circuitry
• 0-20 mA level output
• Relays and heater operation
• Processor watch dog
• Software
• Memory
• Oscillator frequency
4.2
Response to fault indication
If a failure is found, the detector indicates by:
• Light-emitting diode (LED): yellow flashes (4 Hz)
• Fault relay opens
• 0-20 mA: 1 mA default
• Analog voltage output: 0 V output
The fault indications remain until the detector is turned off. The fault indications return if
the fault is still found when power is restored.
4.3
Built-in test (BIT)
The detector's BIT checks the following:
• Sensors
• Window cleanliness
• Electronic circuitry
The detector can be set to perform the BIT in the following modes:
• Automatically and manually
• Manually only
Manual Initial setup
00809-1400-4975 September2023
Rosemount 975 27