BTRs & DNC Software
DNC is Delivering data to computer integrated NC machines
Simply put, you need to connect the shop floor with engineering and
business systems. Or briefly, as manufacturers move from
Functional structure to Process-oriented structure they
"decentralize" to gain flexibility and quality.
Distributed Numerical Control (DNC) was used to save time and money
over manual methods of loading programs, and using punched tape.
Today DNC is an essential element of CIM and production logistics.
Networking eliminates errors, and gives all machines a unified way
to access files. Network security features keep your files safe.
Programs in CNC memory can be saved easily and rapidly, so you will
not loose edited files.
DNC saves money
DNC is constantly improving, and now
is more affordable than ever. You do not have to buy new
machines, or buy an expensive "DNC" options from the machine
manufacturers, to gain the improvements provided by DNC. Advanced
Digital Research Inc. specializes in providing networking for all
types/brands of machines.
Factory machines have a
specialized computer in them, called the "control". The control operates
the machines in real-time. The machine actions are determined
by a program - a command is called a block. Older machines may not
have memory and execute blocks fed to them from a tape reader(NC
machines). ADR's BTR supports hundreds of different NC/CNC models.
We supply cables needed to attach the BTR to the control and have
application notes on how to configure our BTR for almost every
A CNC (computer numerical control) has memory and "devices"
(RS232 ports) to move data in and out of its memory. Some CNC can
only execute programs from their memory, others can "drip-feed" -
execute from an input device, while reading ahead a few blocks.
RS232 has been around a long time, and was originally intended as
the standard for hooking modems to computers and terminals.
A modem allows connection to the public phone system for long or short
distance communication. Now days we "direct connect" CNC to
computers using RS232, or "bridges"(modems) to connect via
Ethernet, BlueTooth, USB and other communication "media".
DNC Server Computers:
The primary role of a DNC server
computer is to store programs, and to send and receive data files. A
DNC Server Computer in simple terms is any computer running a DNC
service program. A network of PC DNC server computers can act like a
single large DNC server computer.
A DNC server computer can also be used to create new programs or edit
programs, but this activity is usually done on a graphic workstation
(or PCs) with CAD capability. Windows has become very
popular in manufacturing, due to its low cost and high performance.
LINUX has become more popular as a server operating system because it is "open sourced", and
there is less "hidden marketing" features than in Windows .
PC manufacturers are no longer providing
RS232 ports and Parallel printer ports on PCs. So applications
supporting serial ports and parallel printers now use USB devices.
The Universal Serial Bus is intended to
connect printers, scanners, keyboards and mice as well as hard
drives to the PC. DB9, DB25 serial ports and DB25 printer port
connectors are not provided on new PC, because of the popularity of
USB. USB is capable of delivering data at a high rate.
connected via USB tend to have limitations compared to the serial
ports that used to be on the motherboard or provided in a ISA or PCI
slot. The problem is that USB is far slower to respond to
interrupts, making "Drip-feed" impossible.
Microsoft Windows is the defacto standard in
manufacturing. Windows 2000/XP/VISTA/Win7/Win8/Win10 are progressively
better operating systems, demanding progressively more powerful computer
plateforms to make them work.
DNC means connecting the company database with
machines. You might dedicate a personnel computer to each machine in
your shop, or you might support all of your machines from one
central computer. ADR can provide you with software and hardware
applicable to both of these choices.
When the NC program is too large to fit into the
CNCs memory, it can still be run, by the PC feeding the data to the
CNC as it needs it. Not all CNC can do this. The problem is to keep
the CNCs buffer full of data without ever going empty, because if
the CNC is "starved for data" the part being machined could be
ruined. Care must be taken to insure that, no corrupted data is ever
processed by the CNC, or data is lost. The PC must remain "ON-LINE"
during the execution of the program, turning the PC off, or
"Suspending" to save power would be a disaster.
DNC Wired Networks
Single Drop (Star) Connections radiate from a central point like spokes on a wheel.
This has proven to be the most reliable way to wire multiple computer and machines
A popular form of Star network is the RS232 DNC system. Since most
machines support RS232 they can be directly attached to inexpensive
com ports in the DNC server computer/network.
Another popular Star network is based on 10/100/1000BaseT
Ethernet. An Ethernet Hub (switch) is used as the central point and
twisted pair wires carry data at 10Mbit/sec, 100Mbit/sec and
These type network are often described as
server/client. The CNC machines are "clients" and the network
is the Server.
ETHERNET DNC Protocols
Newer CNC machines can directly attach to Ethernet,
others require adapters. If your CNC does not support Ethernet
you can connect the CNC's COM port via an Ethernet COM
port. You can then use COM software to transfer files via the
COM port. This allow you to use Ethernet cables, but the
transfer rate is slow.
FTP (File Transport Protocol)
built on TCP/IP) is
standard procedure for accessing server files. Some CNC have a
FTP client access built in. To use this feature, the CNC
establishes a session with an FTP Server, .
Wireless (WIFI) Ethernet DNC
Who needs wires? The best wireless system almost duplicates
the capability of a wire. The goal of wireless is to
save installation cost, and add mobility.
With a advent of powerful handheld device such as the iPhone and iPad.
The ability to store huge NC files in flash memory and handle it with easy
Push and Pull Data
Data transfers can be directed from the DNC server
called PUSH, or remotely requested at the machine called PULL.