Hello,
In order to setup those parameters, you need to connect to the Vera's web interface, then go to Devices tab and click on > button in front of your roller shutter. Then go to Device Options and you should see an option called Configuration settings.
From there please click on Add configuration settings and you'll see that you'll have the option to setup what you want. For variable value, you'll put the parameter that you want ( for example 18 ) then the date size and the desired value.
When you are finished with this, you need to save the changes.
Thank you and Have a nice day