DS Analytic Model oData: all/any value for parameters

[mitko1994]

Hello,

I have an Analytic Model that has  some variables/parameters. When I preview the data only the START_DATE and END_DATE are mandatory. However, when I'm using the oData URL Generator to create URL for data consumption, I'm prompted to fill out all possible variables (see screenshot). 

Question 1: Why is that I need to pass a value for all variables?

Question 2: What can I put to signify all/any value (equivalent to leaving a variable blank in the Data Preview selection prompt)? For example how can I pass a selection for all values for 0PLANT?