Fisher FIELDVUE DLC3010 Instruction Manual page 50

Configuration
October 2014
PV Lo Alert Threshold— Primary Variable Lo Alert Threshold is the value of the primary variable, in engineering
units, which, when exceeded, sets the Primary Variable Low Alert.
PV Lo Alert Threshold— Method to change the PV Lo Alert Threshold
D Lo Lo Alert
PV LoLo Alert Enable— On or Off. PV Lo Lo Alert Enable activates checking the primary variable against the PV Lo Lo
Alert limit. The Lo Lo Alert is set if the primary variable rises above the PV Lo Lo Alert limit. Once the alert is set, the
primary variable must fall below the PV Lo Lo Alert limit by the PV Alerts Threshold Deadband before the alert is
cleared. See figure 4‐7.
PV LoLo Alert Threshold— Primary Variable LoLo Alert Threshold is the value of the primary variable, in engineering
units, which, when exceeded, sets the Primary Variable Low­Low Alert.
PV LoLo Alert Threshold — Method to change the PV Lo Lo Alert Threshold
Note
If the Lo Lo Alert is enabled and set, the digital level controller output will go to below 3.75 mA or above 21.0 mA, depending on
the position of the alarm jumper.
PV Value— Current process variable (level, interface, or density) in engineering units.
Upper Range Value— Highest value of the primary variable that the digital level controller is currently configured to
measure in the 4 to 20 mA loop.
Lower Range Value — Lowest value of the primary variable that the digital level controller is currently configured to
measure in the 4 to 20 mA loop.
PV Alerts Threshold Deadband — The Primary Variable Alerts Threshold Deadband is the amount the primary variable,
in engineering units, must change to clear a primary variable alert, once it has been set. The deadband applies to all
the primary variable alarms. See figure 4‐7.
Figure 4‐7. Process Variable Alert Threshold Deadband (Process Variable High Alert Example)
ALERT IS SET
ALERT IS CLEARED
E0372
50
PROCESS VARIABLE
HIGH ALERT LIMIT
PROCESS VARIABLE ALERT
THRESHOLD DEADBAND
PROCESS VARIABLE
Instruction Manual
D102748X012