From OpenSCADAWiki
Startup and execution
OpenSCADA is from the beginning a program that can be started from the console or terminal by typing openscada. In this way, the program will start with its action messages in this console and the console lock on the user actions waiting, which is the default startup mode in the console-terminal and can be used to operative debugging and control the result of actions and errors. In addition to the typical mode, there are also three other modes that are defined by the transmission of options to the startup command:
- Help mode for the command line parameters — openscada --help.
- Demon mode — openscada --demon, of background or service execution. Means disconnection from the launch console and the background execution, that is, visually the program seems to end immediately, the console releases and blocks all local graphical interface modules such as Qt. Used to launch and execute the program in the service mode such as: SCADA server, PLC execution environment, visualisation server, WEB-interfaces server. Typically, this command is placed into the file of description-forming operating system service, and a few ready-made are currently supplied with OpenSCADA.
- Mode of service-daemon debugging — openscada --noX11, is essentially the typical mode with reporting for actions in the console, but preventing the launch of the local graphical user interface modules, which execution is not possible in a clean console and the inaccessible X server.