With Redline 3.5 the logging can now be configured in the Control Center web interface.
Load the Redline Control Center:
The Dashboard is the initial page that is loaded, click on System View.
Select the Redline Agent you are working on.
Click on the Settings tab.
In the Settings section is the Debug Level which the log level that can be set from 1 to 6, 6 being debug log level.
Set the level to 6.
Click OK to save.