Outside Temperature (v1.2)
Full Name
Lib.Mervis.v1_2.OutsideTemperature
Required Project References
- Lib.Mervis
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 Type | Retain | Mandatory 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 | OutsideTemperatureSelectorType | Yes | No | Temperature selection for heating block | |
| OutsideTemperatureThreshold | real | 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 | |
| EnabledByOutsideTemperature | bool | Heating block INactive | |
| AlarmsStatus | Lib.Mervis.v1_0.AlarmsStatus | Combined interface for alarm indication |
Blocks
| Name | Data Type | Meaning | |||||||||
| Alarms | Lib.Mervis.v1_0.AlarmsExtender1 | Alarm function of the block | Alarm Input | Priority | Meaning | 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.