Based on the following steps we can add the different variables to our expressions.

 

To start the wizard, click on the "Add new" button.

 

 

Then a variable type selection window will come up by which you can select if you want to create a Quantity, Constant, CSV file, ODBC, Quantity, String or User input variable.

 

 

Types of variables:

 

 

Selection and setting of variable:

 

 

After selecting which type of variable we want to create and gave the parameters required for the creation of the variable, the following window will come up:

 

 

In this window we can set that our variable should not take into account the global date/time settings during a query, but work with fixed or relative dates. In case of defining a relative date/time, it is possible to shift the actual time interval compared to the global settings.

 

The setting possibilities are as follows:

 

 

The value can be a negative and a positive integral number between  -2147483648 and 2147483647.

 

As the next step in the window bellow we can define conditions for the evaluation of the variable in order to filter the data samples presented in the data table obtained as a result of the query.

 

 

We can add as argument simple variables and Date/time variable (we can also filter our data sample based on their time stamp).

In the operation field we can specify the operation the result of which will determine of the given data sample can remain in the original variable data table or not.

As soon as we selected our arguments and the operation, we can add the conditions to the list by the Add button (each variable can have unlimited number of condition-variable).

Finally by clicking on the Finish button out variable will get into the expressiongroup variable list.