Dostek DNC

Dostek DNC™

APPLICATION GUIDE

This page includes the following topics to help you use Dostek DNC software:

For information about communication ports and cables, see the Ports and Cables page.

About DNC Systems

A DNC system transfers CNC part programs between a computer and a CNC machine tool's program memory (Distributed Numerical Control), or lets the CNC run programs directly from a computer (Direct Numerical Control, or "drip feed").

Direct Numerical Control lets you:

  • Run programs on NC machines that have no internal program storage.
  • Run large programs on CNC machines with limited internal program storage.
  • Run large programs directly to save the time it would take to load the file into the CNC's program storage.

Distributed numerical control lets you:

  • Use a portable, laptop or netbook computer to load, save and drip-feed CNC programs.
  • Use a single computer to simultaneously load, save and drip-feed multiple CNCs.
  • Use a network of individual computers to load, save and drip-feed CNCs

What You Need

To use Dostek DNC software, you need:

  • A Windows computer.
  • An RS-232C serial communication port.
  • A communication cable.

Most CNCs provide an RS-232C serial port for DNC. In Windows, serial ports are called "COM" ports. Most older computers included one or two built-in COM ports, but COM ports are rarely included in newer computers.

Communication cable requirements vary by CNC model. However, most CNCs require a "cross-linked null modem" cable.

For more information about computer COM ports and communication cables, see the Ports and Cables page.

Drip-Feeding Large Files

To drip-feed large files to a CNC, the program is stored on the computer, and the computer feeds the program as the CNC runs it. Drip-feeding lets you run programs that are too large to fit in the CNC's program storage, or lets you reduce set-up time by eliminating the need to transfer a large file into the CNC's memory.

Drip-feeding is supported by many, but not by all, CNC models. For example:

  • To drip-feed to most newer Fanuc CNC models, select TAPE mode and press CYCLE START.
  • To drip-feed to Fanuc Model 2000, 3000, 5 and 6 CNCs, a Behind-the-Tape Reader (BTR) is required (such as the Dostek Model 440A BTR).
  • To drip-feed to some CNC models, such as Okuma OSP5000, a proprietary hardware or software upgrade is required.

For more information about using Dostek DNC software for drip-feeding, contact Dostek.

Using Multiple CNC Machines

To use Dostek DNC with multiple CNC machine tools, you can:

  • Use a mechanical switch box to connect several machines to the computer's COM port.
  • Use a portable, laptop or netbook computer.
  • Use an individual Ethernet/serial adapter at each CNC machine.
  • Use a single computer by installing a multiple-port serial board in the computer, or by connecting the computer to a multiple-port hub.

For more information about Ethernet/serial adapters, serial boards, and hubs, see the Ports and Cables page.

Using Older NC/CNC Machines

Many older NC/CNC machines are not equipped with a serial communication port. If the machine is equipped with an optical paper tape reader, you can upgrade it for DNC by installing the Dostek Model 440 Behind-the-Tape Reader (BTR) interface adapter. For more information, see the Dostek 440A BTR page.

Working With a Laptop/Notebook/Netbook Computer

A laptop or netbook computer can be an inexpensive and convenient way to transfer files to CNC machine tools. However, most new laptop or netbook computers do not include the built-in serial COM port required for DNC.

Using a USB/serial adapter or serial ExpressCard adapter appears to be an affordable way to add a COM port. However, all of these adapters tested recently include design flaws that can cause problems with CNC communication.

For information about specific problems, suggested alternatives, and an adapter diagnostic tool, contact Dostek.

Working With Your Network

Dostek DNC software works with your office or shop-floor local area network (LAN). You can:

  • Store CNC part program files on a central file server, or on the computer's local hard disk.
  • Use network-connected Ethernet/serial communication adapters to connect to CNC machine tools.

Dostek DNC software is designed to run on a "workstation," rather than a "server." However, Dostek DNC works with many server, "thin client" and "virtual machine" technologies. For more information, contact Dostek.

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