In this section, we will explain how to build a system by combining multiple RTCs created.
Distributed Object Middleware provides transparent access via proxy objects that hold References to objects on the computer at some locations. The reference is called IOR (Interoperable Object Reference) in CORBA, and the actual entity is a character string that encodes the IP address, port number, and object-specific key of the computer where the object exists. One way for a program on another computer to know the IOR of an object is to register the IOR on a server on the network. The service that registers and obtains this reference is the Name Service. The name service is one of the standard services defined in CORBA standards, and it is provided as a wrapper command rtm-naming in OpenRTM-aist.
Before starting up your RT systems, you need to start the name server for registering RTCs. Also, for each RTC, it is necessary to give the name server location in advance in the configuration file rtc.conf'. For example, if you start a name server on the hostname openrtm.mydomain.net'', you need to provide rtc.conf which has the following line for all the RTCs.
The name server can also be specified by the IP address, and by separating it with "," you can register RTC to multiple servers at the same time. Normally, it is not necessary to frequently rewrite the configuration file, since the name server is usually be kept running for a long time and it is a fixed item in the system.
System construction with RTSystemEditor
The system runs by running some created RTCs, connecting and activating those ports. RTSystemEditor is provided as a tool for connecting RTCs, sending activation and deactivation commands to the RTCs, and starting up the system.
When RTC is started, it is displayed in the name service view on the left pane. When RTCs are on the name service view, RTCs can be dragged and dropped to the central editor area. The dropped RTC is displayed as an icon in the system editor. The protrusion on the side of the rectangle represents the port and the system is constructed by connecting the ports between the RTCs. Also, the RTC configuration view is displayed at the lower center of the screen, so you can edit the parameters of the RTC.
After building the system, it is possible to activate all the RTC by right-clicking on the editor and selecting All Activate. You can also save the system configuration information by right-clicking on the editor and selecting Save as. By saving the system configuration information again, it is possible to restore system connection information, configuration information and so on.
Currently, it is necessary to start up RTC beforehand when restoring the system configuration information, but in the future it will be possible to restore all elements from RTC startup to connection restoration.