NOVUS AUTOMATION
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The configuration cycle for alarms
alm1
/
alm2
allows for assigning the psychrometric property associated with alarm outputs
alm1
/
alm2
, the
operating mode for alarms
alm1
/
alm2
(type of alarm), activation points for alarms
alm1
/
alm2
, their timing values, inhibition of alarm condition
when turning the device on, and the alarm activation mode in case of sensor reading error.
The figure below shows how the alarm outputs are activated and deactivated according to the type of alarm selected.
Fig. 23
- Alarm output activation and deactivation
The
RHT
Climate
Transmitter
allows for four timing options for its alarm outputs and for the buzzer:
•
Normal operation;
•
Activation for set time;
•
Delay in activation;
•
Intermittent activation.
The figures in
Table 4
show the behavior of alarm outputs with these activation variations defined by the
T0n
and
T0ff
time intervals.
OPERATION
T0n
T0ff
ACTUATION
Normal operation
0
0
Alarm Event
Alarm
Output
Activation with
set time
1 to 6500 s
0
Alrm Event
Alarm
Output
T0n
Delayed
activation
0
1 to 6500 s
Alarm Event
Alarm
Output
toff
Intermittent activation
1 to 6500 s
1 to 6500 s
Alarm Event
Alarm
Output
T0n
T0ff
T0n
Table 09
- Timing functions for alarms
The
Initial Blocking
option prevents alarm activation if there is an alarm condition when the controller is turned on. The alarm is only enabled after
the process passes through a non-alarm condition.
The initial block is useful, for example, when one of the alarms is configured as minimum value alarm, potentially setting off the alarm right when
the process is started up, which is often undesirable behavior.
Initial blocking is not valid for the Sensor Open function.
