The Upper Limit (Priority of Current Value) and Lower Limit (Priority of Current Value) rule types check whether the most recent measured value is above or below the configured limit value (4000 and 3800 in the example). If the most recent measured value is above or below the limit value, the previous measured values are checked. The event is triggered if the measured values exceed or undershoot the configured limit a set number of times within a given time period (in the example, exceeded or undershot twice per minute).
Rule type variants
Example
The rotational speed of a motor is monitored. An upper limit of 4000 rpm and a lower limit of 3800 rpm have been defined. In addition, two overshoots of the defined limits per minute have been defined.
If the upper limit of 4000 rpm is exceeded three times within one minute, an event is triggered on the third overshoot.