# ForecastOutsideTemp

## `ForecastOutsideTemp` (FB)

FUNCTION\_BLOCK ForecastOutsideTemp

### Short description

> > Forecast of the outside temperature (forecast period and function configurable)\
> > Prerequisite: FB 'WeatherForecast' from the Weather Forecast Library\
> > Constraint: The weather forecast data must be updated at least every 12 hours\
> > Index \_FC: External weather forecast data
>
> Index \_Int: Internal weather forecast data | Typical application: Calculation of the outside temperature for a heating/cooling curve

### Representation

<figure><img src="/files/49db51a70e79d9f41a896a86af321e4fa4211ef8" alt=""><figcaption></figcaption></figure>

### Interfaces

#### Inputs

<table><thead><tr><th width="160">Name</th><th>Data type</th><th>Value range</th><th>Initial value</th><th>Function</th></tr></thead><tbody><tr><td><em>xEn</em></td><td>BOOL</td><td></td><td>FALSE</td><td>Enable - Weather forecast (FALSE = Off, TRUE = On)</td></tr><tr><td>*rOutsideTemp_In’</td><td>REAL</td><td></td><td>-10.0</td><td>Fallback value for the outside temperature</td></tr><tr><td><em>xOutsideTempError_In</em></td><td>BOOL</td><td></td><td>FALSE</td><td>Error state - fallback value for the outside temperature (FALSE = no error, TRUE = error)</td></tr><tr><td><em>rFixedValue</em></td><td>REAL</td><td></td><td>0.0</td><td>Fixed value for the outside temperature</td></tr><tr><td><em>xError_FC</em></td><td>BOOL</td><td></td><td>FALSE</td><td>Error state - weather forecast data (FALSE = no error, TRUE = error)</td></tr><tr><td><em>xDone_FC</em></td><td>BOOL</td><td></td><td>FALSE</td><td>Signal after successful completion of the transfer of the weather forecast data (rising edge)</td></tr><tr><td><em>arData_FC</em></td><td>ARRAY[*] OF WEATHER_FORECAST.WeatherData</td><td></td><td></td><td>Array with the weather forecast data (output 'aForecast' of FB 'WeatherForecast')</td></tr></tbody></table>

#### Outputs

<table><thead><tr><th width="177">Name</th><th>Data type</th><th>Value range</th><th>Initial value</th><th>Function</th></tr></thead><tbody><tr><td>*eMode’</td><td>eForecastOutsideTempMode</td><td></td><td>eForecastOutsideTempMode.Invalid_Mode</td><td>Operating mode (0 = none, 1 = forecast, 2 = outside temperature, 3 = fixed value)</td></tr><tr><td>*eFBPeriod_Int’</td><td>eForecastOutsideTempPeriod</td><td></td><td>eForecastOutsideTempPeriod.Invaild_Period</td><td>Feedback - forecast range - internal weather forecast data (0 = none, 1 = 3 hours, 2 = 6 hours, 3 = 9 hours, 4 = 12 hours, 5 = 24 hours, 6 = 36 hours, 7 = 48 hours, 8 = 72 hours, 9 = 96 hours)</td></tr><tr><td>*eFBFunction_Int’</td><td>eForecastOutsideTempFunction</td><td></td><td>eForecastOutsideTempFunction.Ivalid_Function</td><td>Feedback - function - internal weather forecast data (0 = none, 1 = minimum value, 2 = maximum value, 3 = average value)</td></tr><tr><td>*rOutsideTemp_Out’</td><td>REAL</td><td></td><td></td><td>Calculated outside temperature</td></tr><tr><td><em>xError</em></td><td>BOOL</td><td></td><td>FALSE</td><td>Error state (FALSE = no error, TRUE = error)</td></tr></tbody></table>

#### Setpoints / parameters

<table><thead><tr><th width="175">Name</th><th>Data type</th><th>Value range</th><th>Initial value</th><th>Function</th></tr></thead><tbody><tr><td>**eFBPeriod_Int’*</td><td>eForecastOutsideTempPeriod</td><td></td><td>eForecastOutsideTempPeriod.Time_24_Hours</td><td>Forecast range - internal weather forecast data (0 = none, 1 = 3 hours, 2 = 6 hours, 3 = 9 hours, 4 = 12 hours, 5 = 24 hours, 6 = 36 hours, 7 = 48 hours, 8 = 72 hours, 9 = 96 hours)</td></tr><tr><td>**eFBFunction_Int’*</td><td>eForecastOutsideTempFunction</td><td></td><td>eForecastOutsideTempFunction.Average</td><td>Function - internal weather forecast data (0 = none, 1 = minimum value, 2 = maximum value, 3 = average value)</td></tr></tbody></table>

### Function description

The output rOutsideTemp\_Out is calculated / set depending on the state of the input 'xEn':\
\
xEn = FALSE:\
\
The output rOutsideTemp\_Out takes the state of the fallback value (rOutsideTemp\_Out = rOutsideTemp\_In) if the fallback value is error-free (xOutsideTempError\_In = FALSE).\
The output rOutsideTemp\_Out takes the state of the fixed value (rOutsideTemp\_Out = rFixedValue) if the fallback value is faulty (xOutsideTempError\_In = TRUE).

\
The output eMode is updated accordingly.\
The output xError is set to FALSE.\
The output eFBPeriod\_Int is set to eForecastOutsideTempFunction.Ivalid\_Function.\
The output eFBFunction\_Int is set to eForecastOutsideTempFunction.Ivalid\_Function\
\
xEn = TRUE:\
\
The output *rOutsideTemp\_Out* is set based on the parameters 'ePeriod\_Int' (ePriodInt <> eForecastOutsideTempPeriod.Invalid\_Period) and\
'eFunction\_Int' (eFunctionInt <> eForecastOutsideTempFunction.Invalid\_Function), provided the input 'xError\_FC' is FALSE and the internal error variable is also FALSE. The outputs eFBPeriod\_Int and eFBFunction\_Int adopt the current\
settings of the parameters ePeriod\_Int and eFBFunction\_Int.\
\
The output *rOutsideTemp\_Out* takes the state of the fallback value (*rOutsideTemp\_Out* = 'rOutsideTemp\_In) if the fallback value is error-free (xOutsideTempError\_In = FALSE).\
The output eFBPeriod\_Int is set to eForecastOutsideTempFunction.Ivalid\_Function.\
The output eFBFunction\_Int is set to eForecastOutsideTempFunction.Ivalid\_Function\
\
The output *rOutsideTemp\_Out* takes the state of the fixed value\
(*rOutsideTemp\_Out* = 'rFixedValue) if the fallback value\
is faulty (xOutsideTempError\_In = TRUE).\
The output eFBPeriod\_Int is set to eForecastOutsideTempFunction.Ivalid\_Function.\
The output eFBFunction\_Int is set to eForecastOutsideTempFunction.Ivalid\_Function\
\
The output eMode is updated accordingly.\
The output xError is updated accordingly.

#### Updating the output *rOutsideTemp\_Out*

The output *rOutsideTemp\_Out* is updated (prerequisite: xEn = TRUE) if at least one of the following criteria is met:\
\
Criterion 1: Update of the weather forecast data (rising edge at input xDone\_FC)\
Criterion 2: Change of the start index\
Criterion 3: Change of the forecast range (parameter ePeriod\_Int)\
Criterion 4: Change of the function (parameter eFunction\_Int)\
Criterion 5: Rising edge at input xEn\
\
The start index changes when the current timestamp (= system time) reaches the timestamp of the next element of the weather forecast data.\
The output *rOutsideTemp\_Out* is therefore updated at least every 3 hours.\
The output *rOutsideTemp\_Out* is always calculated in a time-accurate manner, i.e. all elements of the weather forecast data that lie between the time of update and the time of update + forecast range are used for the calculation.\
\
In the event of an internal data error (missing data, faulty data) the output *rOutsideTemp\_Out* is described with an internally defined constant\
(currently: -1000.0) and the state of the internal error variable is set to TRUE.

#### This function block can be applied as follows:

This function block can be applied as follows:

<figure><img src="/files/ef58d1401716a09590d15959e138ba1a57fdb222" alt=""><figcaption></figcaption></figure>

### CODESYS

InOut:

| Scope       | Name                   | Type                                               | Initial                                       |
| ----------- | ---------------------- | -------------------------------------------------- | --------------------------------------------- |
| Input       | `xEn`                  | `BOOL`                                             | TRUE                                          |
| Input       | `rOutsideTemp_In`      | `REAL`                                             |                                               |
| Input       | `xOutsideTempError_In` | `BOOL`                                             | FALSE                                         |
| Input       | `rFixedValue`          | `REAL`                                             | 0.0                                           |
| Input       | `xError_FC`            | `BOOL`                                             | FALSE                                         |
| Input       | `xDone_FC`             | `BOOL`                                             | FALSE                                         |
| Input       | `arData_FC`            | <p>POINTER TO<br>WEATHER\_FORECAST.WeatherData</p> |                                               |
| Output      | `eMode`                | eForecastOutsideTempMode                           | eForecastOutsideTempMode.Invalid\_Mode        |
| Output      | `eFBPeriod_Int`        | eForecastOutsideTempPeriod                         | eForecastOutsideTempPeriod.Invaild\_Period    |
| Output      | `eFBFunction_Int`      | eForecastOutsideTempFunction                       | eForecastOutsideTempFunction.Ivalid\_Function |
| Output      | `rOutsideTemp_Out`     | `REAL`                                             |                                               |
| Output      | `xError`               | `BOOL`                                             | FALSE                                         |
| Input Const | `eFunction_Int`        | eForecastOutsideTempFunction                       | eForecastOutsideTempFunction.Average          |
| Input Const | `ePeriod_Int`          | eForecastOutsideTempPeriod                         | eForecastOutsideTempPeriod.Time\_24\_Hours    |

Methods:

> mApplyFunction\_Int

> mCalculateOutsideTempOut\_Int

> mCalculateStartIndex\_Int

> mResetData\_Int

> mUpdateData\_Int

Structure:

* mApplyFunction\_Int (Method)
* mCalculateOutsideTempOut\_Int (Method)
* mCalculateStartIndex\_Int (Method)
* mResetData\_Int (Method)
  * Resetting all internal weather forecast data to invalid values \*\*\*
* mUpdateData\_Int (Method)


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