1.6
Internal detector tests
The detector performs two types of self-tests:
•
•
1.6.1
Continuous feature test
The detector is supplied with default settings, containing Continuous Feature Test. To
change these settings, refer to 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
Response to a fault indication
If a failure is found, the detector indicates it by:
•
Fault relay:
—
Opens in output configurations 1A, 2A, and 1R
—
Closes in output configurations 3A and 2R
•
0-20 mA: indicates fault (0 mA or 2 mA) in output configurations 1A, 2A, and 3A
•
LED - yellow flashes (4 Hz)
•
Correcting the fault
The fault indications remain until the detector's power is removed. The fault indications
return if the fault is still found when power is restored.
1.6.2
Built-in test (BIT)
The detector's built-in test (BIT) also checks the following:
•
Electronics circuitry
Reference Manual
Introduction
00809-0100-4976
June 2021
Rosemount 975HR
25
Legacy
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Страница 42: ...Installing the detector Reference Manual June 2021 00809 0100 4976 42 Emerson com Rosemount L e g a c y ...
Страница 66: ...RS 485 communication network Reference Manual June 2021 00809 0100 4976 66 Emerson com Rosemount L e g a c y ...
Страница 78: ...SIL 2 features Reference Manual June 2021 00809 0100 4976 78 Emerson com Rosemount L e g a c y ...