NEX7250 Zone 2 Annunciator
33
12.3 ISA-A-4 Sequence
- Non Lock-In Function
SEQUENCE TABLE
LINE
PROCESS
CONDITION
PUSHBUTTON
OPERATION
SEQUENCE
STATE
VISUAL
DISPLAY
ALARM
AUDIBLE
DEVICE
REMARKS
1
NORMAL
NORMAL
OFF
SILENT
2
ABNORMAL
ALARM
FLASHING
AUDIBLE
3
RETURN TO NORMAL BEFORE
ACKNOWLEDGE
NORMAL
OFF
SILENT
NON LOCK IN
4
ABNORMAL
ACKNOWLEDGE
ACKNOWLEDGED
ON
SILENT
MAINTAINED
ALARM
6
NORMAL
NORMAL
OFF
SILENT
AUTOMATIC
RESET
SEQUENCE FEATURES
1. ACKNOWLEDGE AND TEST PUSHBUTTONS
2. ALARM AUDIBLE DEVICE
3. NON LOCK-IN OF MOMENTARY ALARMS
4. THE AUDIBLE DEVICE IS SILENCED AND FLASHING STOPS WHEN ACKNOWLEDGED
5. AUTOMATIC RESET OF ALARM INDICATIONS WHEN PROCESS CONDITIONS RETURN TO
NORMAL BEFORE OR AFTER ACKNOWLEDGE (NON LOCK-IN)
6. OPERATION TEST
RETURN
TO NORMAL
SEQUENCE ISA A - 4
(NON LOCK IN)
AUDIBLE
VISUAL
SILENT
ON
ACKNOWLEDGED
PROCESS
ABNORMAL
ACKNOWLEDGE
WHILE ABNORMAL
AUDIBLE
VISUAL
SILENT
AUDIBLE
PROCESS
AUDIBLE
FLASHING
ALARM
TO
ABNORMAL
SEQUENCE DIAGRAM
NORMAL
OFF
NORMAL
VISUAL
PROCESS
RETURN
TO NORMAL
SEQUENCE
SEQUENCE
SEQUENCE
ABNORMAL
OR NORMAL