Glossary Item Box
Activities that represent DSS services may require configuration information about how they should start. These settings are referred to as the initial state. In addition, partner services may also need to be started. Service details are displayed in the Properties window when a service activity block is selected. Setting the initial configuration can be accomplished by displaying the Set Configuration page. Click on Set Configuration from the Edit menu, or the service's Context Pop-Up Menu, or by double clicking the Service Block.
Depending on the service, you may have one of four options to set the initial configuration of a service.
Set initial configuration
A service can have an initial state which includes its configuration. By setting its initial state you configure the service. Configuration can include state properties like its serial communications port and baud rate. It can also include physical properties. These initial configuration properties can be set either in the Properties window or on the Initial State tab of the Set Configuration page.
Some services may define partners used for their operation. Partners are other services that provide support for a service. For the partners, you can define the specific service the partner will use as well as the configuration properties for that service.
You can define what services to use for partners by dragging them from the Services toolbox to their entries on the Partners tab of the Set Configuration page. You can then set the configuration for the partner services.
When you set the initial configuration of a service, VPL adds a file for this to your project. If a service is deleted, and its initial configuration has been set, VPL will display a warning asking to confirm the deletion since doing so will also delete its configuration file. The configuration file can also be deleted by selecting it, displaying its context pop-up menu, and clicking Delete.
If you delete the configuration file, you can restore its default configuration parameters by clicking the Create Initial State that appears in the Properties window or the configuration page for the service. You can also import a pre-existing configuration file and its parameters by clicking the Import Initial State button.
Use another service
This setting enables you to use the configuration information of other services to initialize your service. You can select a specific service to use by dragging a specific service to the configuration page. Or you can select the Use Existing Service or Create a New One option which will request the Decentralized Software Services (DSS) runtime to find a compatible running service or try to start an appropriate service and use its configuration. This enables you to use generic services in the diagram and simply change the actual service to be used at runtime without changing your diagram. The selected service can also be configured.
Use a manifest
This option enables you to select an existing manifest file to start the service. A manifest is a special file that describes a set of services to be started and their configurations. Use the Import Manifest command to display a list of existing manifest files. Then select a service that is started by this manifest. You can also choose to let the DSS runtime find or create an appropriate service.
This option indicates that you want to start the service without any specific configuration. This is the default option. The option is appropriate for most simple services. Good examples include the Math Functions, Simple Dialog, or Text-To-Speech services.
VPL User Guide: Running And Debugging
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