Emerson 3308A Rosemount 3308 Series Reference Manual page 187

Reference Manual
00809-0100-4308, Rev BA
User Defined Alert
Enable User Defined Alert
Variable
Alert Direction
Limit
Deadband
Lost Measurement
Lost Measurement Behavior Configure level value to report if measurement is lost
Number of Measurements to
Hold Level
Configuration Parameters
Appendix D: Configuration Parameters
If the alert will be enabled or not.
The variable selected for the alert.
Whether the alert will be triggered above or below the
variable's value.
The variable value that will trigger the alert.
Note
Alert Limit values must be outside the Upper Null Zone, the
Blind zones, and areas close to the Blind Zones with reduced
accuracy.
An area of a variable's range where no action occurs to
prevent alert from activating/deactivating too quickly.
unexpectedly. Choose one of the following actions:
Lost Measurement Description
Behavior
Alarm (NaN Value/ If the measurement is lost, the level
Bad Status) value will report:
"Not a Number / Bad Status".
Output Full Tank If the measurement is lost, the level
value will correspond to full tank.
Output Empty Tank If the measurement is lost, the level
value will correspond to empty
tank.
The number of measurements the device will hold the current
level if level measurement has been lost. Then it will output
level according to Lost Measurement Behavior, if still lost.
For an application where problems with lost measurement
due to noise or weak surface echoes are experienced, this
parameter value could typically be increased.
The Hold Time value presents for how long the device will
hold the current level. The time the current level will be held is
calculated out of a combination of both Number of
Measurements to Hold Level and the Update Rate.
Note
Make sure you have enough safety margin in your system to
manage a delayed condition.
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