Process Alarm - ABB Navigator 550 Operating Instructions Manual

Navigator 500
Hydrazine analyzer

7.1.6 Process Alarm

Menu
Process Alarm
Select
Exit
Menu
Alarm 1 to 8
Source
Type
Tag
Trip
Hysteresis
Time Hysteresis
Process alarm examples
Process variable
Fig. 7.2 High and low process alarm action
Process variable
Alarm on
Alarm acknowledged by operator
Fig. 7.3 High and low latch alarm action
48
Used to configure up to 8 independent process alarms.
Comment
Selects the analog value for the process alarm source.
Selects the alarm type from:

High Process

Low Process

High Latch

High Latch
The alarm Tag is displayed as a diagnostic message and appears in the
Diagnostic Status Bar and on the Diagnostic View page at Operator level –
see page 28.
The alarm trip level in engineering units.
The hysteresis trip level in engineering units. Activated at the alarm trip level
but deactivated only when the process variable has moved into the safe
region by an amount equal to the hysteresis value – see Process alarm
examples below.
If an alarm trip value is exceeded, the alarm does not become active until
the Time Hysteresis value has expired. If the signal goes out of the alarm
condition before the Time Hysteresis has expired, the hysteresis timer is
reset.
Hysteresis
Alarm on
High process
Alarm off
Hysteresis
Alarm latched
High latch alarm
Hysteresis
Low process
Process Variable
Trip
point Hysteresis
Alarm On
Alarm acknowledged by operator
Alarm off
Low latch alarm
Default
None
High Process
Alarm <n>
0.0
0.0
0
Trip point
Alarm on
Alarm off
Trip point
Alarm latched
Alarm off
OI/AHM550–EN Rev. A