Aalborg Vortex - Manual (Page 34)

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optically isolated output is assigned to the Flow Alarm event, in some cases,
the Flow Alarm Latch feature may be desirable.
5.3.4.2 Submenu L2 Temperature Alarm (*optional)
Vortex flow meter with T/P option provides the user with a flexible alarm/warning
system that monitors the Fluid Temperature for conditions that fall outside config-
urable limits as well as visual feedback for the user via the LCD or via an optically
isolated outputs.
The temperature alarm has several attributes which may be configured by the user
via LCD/Keypad or digital communication interface. These attributes control the
conditions which cause the alarm to occur and to specify actions to be taken when
the temperature value is outside the specified conditions.
Temperature Alarm conditions become true when the current temperature reading
is equal or higher/lower than corresponding values of high and low temperature
alarm levels. Alarm action can be assigned with preset delay interval (0-3600 sec-
onds) to activate the optically isolated output (separate for High and Low alarm).
Latch Mode control feature allows each optical output to be latched on or follow
the corresponding alarm status.
Following settings are available for Temperature Alarm (see Figure 5.8):
a) Temperature Alarm Mode Tabular entry
This function determines whether Temperature Alarm is Enabled or
Disabled. The following selections are available: Enabled or Disabled. The
default entry is Disabled. Alarm Mode selections can be set with the Up
and Dn buttons and are accepted by pressing ENT button.
b) Low Temperature Alarm Numerical entry
The limit of required Low Temperature Alarm value can be entered in
currently active Temperature Engineering units.
If a Low Temperature Alarm occurs, and one of the two optical outputs is assigned
to the Low Alarm Event (see Section 5.3.6.2) the optically isolated output
will be activated when the process temperature is less than the Low Temperature
Alarm value. The Low Temperature Alarm condition is also indicated on the corre-
sponding Process Information Screen by displaying L character.
NOTE: The value of the Low Temperature Alarm must be less than
the value of the High Temperature Alarm.