6.4.3 Configure alarm
The DULCO
®
turb C is equipped with two
independently programmable alarm
relays. Three items of information have to
be entered in order to fully configure the
alarms:
n
Alarm function: HI, LO, OFF or
ERROR
n
Alarm limit value (limit value at which
the alarm becomes active)
n
Alarm delay time (how long the limit
value must be exceeded before the
alarm is activated and the period of
time before the alarm is reset)
Alarm function
Alarm triggering in the event of
an internal system error
The relay produces an alarm in the
event of an internal system error,
regardless of the configured turbidity
values.
You can either deactivate the alarm (OFF)
or program it so that it works in accord‐
ance with one of the following modes:
n
Alarm HI: The relay triggers the alarm
in the event that the turbidity value
exceeds the programmed alarm value
for at least the specified period of time
n
Alarm LO: The relay triggers the
alarm in the event that the turbidity
value drops below the programmed
alarm value for at least the specified
period of time
n
Alarm ERROR: The relay triggers the
alarm when an internal system error
occurs
Limit value alarm
The turbidity threshold at which the alarm
is triggered is referred to as the
‘Limit
value alarm’
. You can configure the limit
value across the entire display range of
the device in steps of 0.01 NTU.
Delay period alarm
The alarm delay times prevent the alarm
from being triggered in the event that the
turbidity briefly exceeds or drops below
the threshold value. The delay function
works as follows:
n
Delay time
‘Alarm on’
: The turbidity
must exceed the
‘Limit value alarm’
for at least the number of seconds set
here before the alarm is activated. If
the time of the
‘Delay alarm on’
is set
to 5 seconds and the turbidity
exceeds the
‘Limit value alarm’
for
only 4 seconds, the alarm will not be
activated. However, if the turbidity
exceeds the
‘Limit value’
for 5 sec‐
onds or longer, the sensor triggers an
alarm.
n
Delay time
‘Alarm off’
: The turbidity
must remain under the
‘Limit value
alarm’
for at least the number of sec‐
onds set here before the alarm is
deactivated. If the time of the
‘Delay
alarm off’
has been set to 5 seconds
and the turbidity remains under the
‘Limit value alarm’
for only 4 sec‐
onds, the alarm will not be deacti‐
vated. As soon as the turbidity
remains below the
‘Limit value alarm’
for at least 5 seconds, the sensor
deactivates the alarm.
Commissioning
40
