Alarm - Brainchild C21 User Manual

3-4 Alarm

3-4 Alarm
The output 2 can be selected as alarm output. There are 6 types of
alarm functions and one dwell timer can be selected, and four kinds of
alarm modes ( ALMD ) are available for each alarm function.
A A process alarm process alarm
higher than SP2, a process high alarm higher than SP2, a process high alarm
is off as the process is lower than SP2-O2HY. When the process is is off as the process is lower than SP2-O2HY. When the process is
lower than SP2, a process low alarm lower than SP2, a process low alarm
off as the process is higher than SP2+O2HY. A process alarm is off as the process is higher than SP2+O2HY. A process alarm is
independent of set point. independent of set point.
A A deviation alarm deviation alarm
from set point. When the process is higher than SV+SP2, a deviation from set point. When the process is higher than SV+SP2, a deviation
high alarm high alarm (DE.HI) (DE.HI)
than SV+SP2-O2HY. When the process is lower than SV+SP2, a than SV+SP2-O2HY. When the process is lower than SV+SP2, a
deviation low alarm deviation low alarm
is higher than SV+SP2+O2HY. Trigger level of deviation alarm is is higher than SV+SP2+O2HY. Trigger level of deviation alarm is
moving with set point. moving with set point.
A A deviation band alarm deviation band alarm
The two trigger levels are The two trigger levels are
process is higher than ( SV+SP2 ) or lower than ( SV - SP2 ), a process is higher than ( SV+SP2 ) or lower than ( SV - SP2 ), a
deviation band high alarm deviation band high alarm
the trigger levels, a deviation band low alarm the trigger levels, a deviation band low alarm
In the above descriptions In the above descriptions
control which is different from SP1 as the ramp function is performed. control which is different from SP1 as the ramp function is performed.
There are four types of alarm modes available for each alarm function, There are four types of alarm modes available for each alarm function,
these are: Normal alarm, Latching alarm, Holding alarm and Latching/ these are: Normal alarm, Latching alarm, Holding alarm and Latching/
Holding alarm. They are described as follows: Holding alarm. They are described as follows:
Normal Alarm : ALMD = NORM Normal Alarm : ALMD = NORM
When a normal alarm is selected, the alarm output is de-energized
in the non-alarm condition and energized in an alarm condition.
Latching Alarm : ALMD = LTCH Latching Alarm : ALMD = LTCH
If a latching alarm is selected, once the alarm output is energized, it
will remain unchanged even if the alarm condition is cleared. The
latching alarm is reset when the RESET key is pressed, once the alarm
condition is removed.
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sets two absolute trigger levels. When the process is sets two absolute trigger levels. When the process is
alerts the user when the process deviates too far alerts the user when the process deviates too far
occurs and the alarm is off as the process is lower occurs and the alarm is off as the process is lower
(DE.LO) (DE.LO) occurs and the alarm is off as the process occurs and the alarm is off as the process
presets two trigger levels relative to set point. presets two trigger levels relative to set point.
SV+SP2 SV+SP2
( DB.HI ) ( DB.HI )
SV SV denotes the current set point value for denotes the current set point value for
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( PV.HI ) ( PV.HI ) occurs, and the alarm occurs, and the alarm
( PV.LO ) ( PV.LO ) occurs and the alarm is occurs and the alarm is
and and SV - SP2 SV - SP2 for alarm. When the for alarm. When the
occurs. When the process is within occurs. When the process is within
(DB.LO) (DB.LO) occurs. occurs.