Function Block LOGGER

The function block LOGGER writes statistics for a variable to the database.

Note: The logger is only displayed on the visualization if the permission at the symbol is met.

All information about statistics can be found in the chapter Logger and Statistics.

Warning: This function block can lead to increased system load or overload at short intervals. Data is automatically deleted at a too small interval. Values are lost and may be incorrect as a result.

Database

The database not only defines the memory of the function block. It also defines the name of the logger's database. Note that you cannot simply rename it, otherwise a new database will be created. It is recommended to use a prefix such as logger.Temperature.

To remove or clear a database, you can do this under the context menu Data ▸ Statistics by removing the corresponding element. After applying all recorded data is lost.

Input IN

The input expects a number. This can be of type Integer (integer) or Float (floating point). If the value NULL, FALSE or an empty string is present when creating the logger, the logger will not be created.

It does not need to be specified which value should be logged. The maximum and minimum values as well as the average value in the interval from input PT are logged. This is calculated each time the database is evaluated. In addition, values are supported as increments. The values can then be displayed differentially with the setting.

When logging energy data, it must be ensured that the unit is stored without SI prefix. If a value of KW comes from an interface, this must be multiplied by 1000.

Tip: To log a binary value, use the function block RT_UPTIME and set the same value for input PT as in the logger.

Input PT

Defines the interval in the format T#. If the input is not defined or the value NULL is present, T#1s is assumed. The input can also be changed dynamically. For example, during irrigation, the moisture measurement can be stored with high resolution.

It is recommended to choose as large an interval as possible. An interval of T#1m to T#15m is completely sufficient for logging a room temperature.

Note: The interval has been limited to T#15m on the Nano, Pico and Touch servers. On all other servers, this is at T#1s.

Input DIS

If the input is true, it disables logging a value to the database. The average calculation is interrupted but not reset.

Output Q

Outputs the same value as input IN. Thus, the function block can be inserted into an existing connection of two function blocks.

Output PT_MIN

The output returns the smallest possible interval to prevent a buffer overflow. The variable is set by the logger service when a new entry is written.