NEX7250 Zone 2 Annunciator
31
12. Sequence Configuration and Tables
Each pair of alarm channels can be configured to suit the operating sequence required, as listed in
the ISA publication "Annunciator sequences and specifications" S18.1 1979.(R2004). Systems can
be configured with different features on each individual channel and there is no need to switch the
power off when making these changes. Different operating modes can be selected using the integral
Pushbutton/Programming module as described later in this manual. The following tables show the
most commonly used examples.
12.1 ISA-Sequence M
- Manual Reset
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
LOCK-IN
3
ABNORMAL
OR NORMAL
ACKNOWLEDGE
ACKNOWLEDGED
ON
SILENT
MANUAL
RESET
REQUIRED
4A
ABNORMAL
RESET
TO LINE 3
4B
NORMAL
RESET
NORMAL
OFF
SILENT
MANUAL
RESET
SEQUENCE FEATURES
1. ACKNOWLEDGE, RESET AND TEST PUSHBUTTONS
2. ALARM AUDIBLE DEVICE
3. LOCK-IN OF MOMENTARY ALARMS UNTIL ACKNOWLEDGED
4. THE AUDIBLE DEVICE IS SILENCED AND FLASHING STOPS WHEN ACKNOWLEDGED
5. MANUAL RESET OF ACKNOWLEDGED ALARM INDICATIONS AFTER PROCESS CONDITIONS
RETURN TO NORMAL
6. OPERATION TEST
N O R M A L
O F F
N O R M A L
S IL E N T
S E Q U E N C E D IA G R A M
S E Q U E N C E IS A M
( M A N U A L R E S E T )
V IS U A L
P R O C E S S
V IS U A L
A U D IB L E
O N
S IL E N T
A C K N O W L E D G E D
A C K N O W L E D G E
R E S E T
W H IL E N O R M A L
A U D IB L E
P R O C E S S
A B N O R M A L
P R O C E S S
V IS U A L
A U D IB L E
F L A S H IN G
A U D IB L E
A L A R M
T O
A B N O R M A L
O R N O R M A L
A B N O R M A L
O R N O R M A L
S E Q U E N C E
S E Q U E N C E
S E Q U E N C E
