Distributed Numerical Control
Distributed Numerical Control ( DNC ) in manufacturing technology describes the embedding of computer-controlled machine tools ( CNC machines) in a LAN or WLAN . If necessary, the machining programs are loaded into the machine control from a central server using the DNC system. DNC systems make it possible to turn away from the punched tape or the diskette as a data carrier . It was only made possible by the development of a network technology that is relatively insensitive to interference with the conditions prevailing in factory halls (large distances to be bridged, strong electromagnetic fields, resistance to oil and acids, insensitive to temperature fluctuations).
Modern CNC machines have an Ethernet interface with an RJ45 socket and can thus be integrated directly into the local computer network. However, there are still machines with a serial interface RS-232 according to EIA-232. These machines are now integrated into the LAN with an RS-232 / Ethernet adapter . PCs with serial interfaces or RS-232 interface cards have been replaced by a client-server architecture in the course of time . The DNC runs as an application on a central server. The NC programs are managed in a database. This removed a limitation of 256 machines in a DNC. The operator can validate, enable or block NC programs on a PC client. Today the DNC is an important tool to ensure traceability in production. It logs every program transfer from and to the CNC machine. The programs are managed with the DNC in a closed system. Every manipulation of an NC program is logged by the DNC. Therefore, even in the age of networkable CNC machines, a DNC is indispensable for production in sensitive industries (medical technology, automotive industry, aircraft industry, etc.).
- Richard Rieger: Industrial terminals support valve production , Maschinenmarkt 11/2010