DAVIS WeatherLink for Alarm Output Add. User Manual
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• A True or False check is used for the Low Transmitter and Repeater
Battery Status parameters, which are not numeric. This check type can
also be used with the Bar Trend parameters.
• Trending allows you to determine whether a particular variable is
approaching a value of concern. It is like a “predictive” alarm. If the
number you enter in the first edit box is lower than the number you enter
in the second box, the data logger will check for an upward trend. Like-
wise, if the number in the first edit box is higher than the number you
enter in the second box, the data logger will check for a downward
trend. The third edit box is used to indicate the maximum period of time
that may elapse before this alarm is no longer valid.
For this type of alarm to be valid, the parameter of interest must pass
through both thresholds within the specified time period. If the parame-
ter is between the thresholds when the alarm is set, or above the higher
threshold for an upward trend alarm or below the lower threshold for a
downward trend alarm, the alarm will not become active. Please note
that frequent communication with the data logger will cause the timing
function of this alarm type to run long.