Table of Contents

Outside Temperature (v1.2)

Full Name

Lib.Mervis.v1_2.OutsideTemperature

Required Project References

Description

Block used for processing outside temperature, calculating average daily temperatures, and blocking heating.

Usage in ST

program test
    var
        ot: lib.mervis.v1_2.OutsideTemperature;
    end_var

    ot();
end_program

Inputs

Name Data TypeRetainMandatory to Connect Meaning
Measured real No Yes Measured temperature from the sensor
FailoverTemperature real Yes No Fallback outside temperature in case of sensor failure
FilterConstant time No No Filter time constant for sensor value filtering
SlowFilterConstant time No No Time constant for a very slow filter for sensor value filtering - used e.g., to distinguish between summer/winter. If set to zero value, the filter is not used
AlarmPriority AlarmPriorityType No No Priority of the alarm generated in case of sensor failure
ThresholdSelector OutsideTemperatureSelectorTypeYes No Temperature selection for heating block
OutsideTemperatureThresholdreal Yes No Temperature threshold for heating block

Outputs

Name Data Type Meaning
OutsideTemperature real Processed outside temperature
AverageYesterday real Yesterday's average outside temperature
AverageTwoDayBefore real Average outside temperature two days ago
AverageThreeDayBefore real Average outside temperature three days ago
TwoDayAverage real Average outside temperature over the last two days
ThreeDayAverage real Average outside temperature over the last three days
SlowOutsideTemperature real Slow outside temperature - used e.g., for switching between summer/winter
EnabledByOutsideTemperaturebool Heating block INactive
AlarmsStatus Lib.Mervis.v1_0.AlarmsStatusCombined interface for alarm indication

Blocks

Name Data Type Meaning
AlarmsLib.Mervis.v1_0.AlarmsExtender1Alarm function of the block

Alarm InputPriorityMeaning
Alarm1 see AlarmPriority Sensor failure

Detailed Function Description

The block processes the value from the outside temperature sensor using the SafeInput block. A sensor failure is evaluated based on the measured value, and an error is reported if it is outside the range of -50..90 °C. This value is then processed and the meteorological daily average temperature is calculated (i.e., the average of the temperature at seven, fourteen, and twice at twenty-one hours). Furthermore, it compares the selected temperature with the current one and deactivates the output used for heating block if necessary.

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