Figure 8. The practical model of an NC VRM
Figure 9. The practical model of a Process Control VRM: AGV approaches ASRS (Automated Stor- age and Retrival System) to load a pallete
station 1 to the station 2. In the station 2, the 6-axis robot VRM transfers the sample material from the palette to the clamps of the cleaning machine. The PLC CS VRM starts to cleaning the sample material using an air compressor. then after loading the palette, AGV moves from the station 2 to the station 3. The 4-axis robot assembles the bolt into a hole of the sample material at the station 3. After finishing the assembling process, the AGV moves from the station 3 to the station 4 and unload the palette at the station 4 (Fig. 17).
The overall scenario can be scheduled by the MMS user. For reference, the source of the VRMs and the MOTIP program can be downloaded from the site at .
MIMS is designed for simultaneous monitoring and controlling the status of multiple clients. MIMS transfers the operational information of the virtual factory to an MMS administrator and external MMS users. Therefore, MIMS can concurrently monitor the status of each networked VRM and several MMS-CS services.
The structure of MIMS is shown in Fig. 18. The MIMS is composed of MOTIP application program, the application program using MMS-CS, and each networked VRM.
MIMS is designed for up to 100 multiple users. MMS users can download the MMS-CS and the client specific program from the site at . Whenever MMS clients uses the downloaded program based on the MMS-CS, MIMS can monitor the operation status through the user information and the communication data between MMS client and server.
The administrator can monitor all the messages from the multiple clients and check the problems in the networked system. The MMS user can then fix their technical problem through the on-line advisories from the MMS server administrator. Therefore, the developed system can serve as a training tool for MMS developers and users.