Wireless DNC

In this article the technical information on wireless data transfer with reference to CNC machine & a Computer is given. The term DNC means Distributed Numerical Control or Direct Numerical Control. CNC machines are Computerized Numerically Controlled Machines. These are very widely used in Automobile, Engineering, Sheet Metal, Aeronautic Industry. These machines are capable of producing different parts. For each type of part, a sequence of instructions is needed. It is called as program. Since this program is producing a part, it is most commonly called as part program. Now most of CNC machine users write a part program on a PC/Laptop. When a part is to be produced this part program (Or file) is up loaded to CNC machine by RS-232 link.

Now this RS-232 link between a PC & CNC machine with a Software is called a DNC System.In a typical shop floor, it is difficult to maintain the data cable. Hence wireless data transfer has come into existence. There are mainly two types of wireless hardware units available in the market. One is using wireless Bluetooth Technology, while the other uses wireless Wi-Fi technology.

In case of Bluetooth, generally one pair of Bluetooth device is used. One gets plugged on COM port of a PC or Laptop & the other is connected to RS-232 port of a CNC machine. The wireless link is established with the required driver software. Once this is established, the user can run his DNC Software for data transfer. In most of the cases, the file is sent from a remote PC to a selected CNC machine.

In Wi-Fi technology, a wireless link is established between a device called Wireless access point (Generally near PC) & a device called as wireless node, which is interfaced near CNC. There is one Access Point & multiple nodes. Each wireless access point, wireless node has one IP address. This IP address must be of the same domain name of a PC. Thus a wireless Ethernet link is created. The wireless node has RS-232 port, which is connected to a RS-232 port of a CNC. There is a driver software on PC which maps the RS-232 port of wireless node as a virtual COM Port of a PC. Once this is done, a DNC Software takes care of two way data transfer.