LIST OF COMMON FILE FORMATS

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  GLOSSARY OF DNC TERMS

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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

ASCII - An acronym for American Standard Code for Information Interchange. ASCII files are plain, unformatted text files that are understood by virtually any computer. Windows Notepad and virtually any word processor can read and create ASCII files. ASCII files usually have the extension .TXT (e.g., README.TXT).

AMI BTR - The AMI is a Universal Behind the Tape Reader (BTR) adapter that interfaces any NC or CNC to a PC via RS232 or RS422.

Request Additional Information and Pricing by contacting us at see also BTR

Anonymous FTP - Is a means by which archive File Transfer Protocol sites allow general access to their archives of information. These sites create a special account called "anonymous". User "anonymous" has limited access rights to the archive host, as well as some operating restrictions. In fact, the only operations allowed are logging in using FTP, listing the contents of a limited set of directories, and retrieving files. Some sites limit the contents of a directory listing an anonymous user can see as well. Note that "anonymous" users are not usually allowed to transfer files TO the archive site, but can only retrieve files from such a site. See also FTP

AUTOEXEC.BAT - A special batch file that the MS-DOS operating system automatically runs when you start or restart your computer. This file contains start-up commands that configure your system.

B

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Backbone - A high-speed line or series of connections that forms a major pathway within a network.

Bandwidth - Refers to the volume of data that can be sent through a connection. This is usually measured in bits-per-second. A full page of text is about 16,000 bits. A fast modem can move about 50,000 bits in one second.

Baud Rate - The transmission speed of data through an asynchronous channel. Often confused with BPS (bits per second), baud rate actually refers to the number of signals per second. Because each signal can represent more than one bit of data, the number of bits per second is usually higher than the baud rate. For example, 2400 bps is typically sent at a rate of 600 baud.

BBS - An abbreviation for bulletin board service.

Binary File - A file that contains data or program instructions written in ASCII and extended ASCII characters.

There are basically two kinds of computer files, binary and ASCII (also called text-only) files. Computer programs, graphic files and word processor documents are all examples of binary files. These files contain special formatting and computer codes. ASCII files are plain text files that can be read by virtually any word processor.

BMP - This is a Windows-based graphic file format used by Paintbrush and other popular paint programs. BMP graphics, like BCX, PCX, TIFF, are a collection of dots rather than shapes. These dots represent an image.

BTR Stands for Behind-Tape-Reader interface. It is a device that provides older machine tools, that were not equipped originally with a capability to communicate directly with a computer, with a means to communicate. BTR interfaces have the following:

See AMI Advanced Machine Interface - ADR's BTR

BPS - Stands for bits per second (Bits Per Second). This represents the number of data bits that a device such as your modem can transfer within a second. This term is often confused with baud rate.

Bytes - A collection of eight bits that represent a character, letter or punctuation mark.

C

CAD - Acronym for Computer-Aided-Design. This is used to describe the process of using a computer to first design a part (CAD) and then a computer to develop the NC programs to machine (CAM) the part. CAM Computer-Aided-Manufacturing.

CAS - Acronym for Communications Applications Specifications. This is a communication standard developed jointly by DCA Inc. and Intel Inc.

Category 3 -Network cable with performance for vice and data transmission up to 16 MHz or 10 Mbps, such as 10BASE-T.

Category 4 -Network cable with performance for vice and data transmission up to 20 MHz or 16 Mbps, such as 10BASE-T.

Category 5 -Network cable with performance for vice and data transmission up to 100 MHz or 100 Mbps, such as 100BASE-T (twisted pair Ethernet).

CGI - (Common Gateway Interface) -- A set of rules that describe how a Web Server communicates with another piece of software on the same machine, and how the other piece of software (the “CGI program”) talks to the web server. Any piece of software can be a CGI program if it handles input and output according to the CGI standard. Usually a CGI program is a small program that takes data from a web server and does something with it, like putting the content of a form into an e-mail message, or turning the data into a database query.

CIM - Acronym for Computer-Integrated-Manufacturing is a high technology approach to more efficient manufacturing throughout the entire manufacturing process.

Clipboard - The Windows Clipboard stores information you "cut" or "copied" from an application. This temporary storage bin lets you move text, graphics and other types of information from one application to another. The information in the Clipboard is static and will not reflect later changes.

Client - A software program that is used to contact and obtain data from a Server software program on another computer, often across a great distance. Each Client program is designed to work with one or more specific kinds of Server programs, and each Server requires a specific kind of Client. A Web Browser is a specific kind of Client.

CNC - Computerized Numerical Control Refers to machine tools that have a computer and memory to control their operation.  Most all non manual machine tools sold today will be CNC.  see also NC

Cookie - On the Internet a “Cookie” is a piece of information sent by a Web Server to a Web Browser that the Browser software is expected to save and to send back to the Server whenever the browser makes additional requests from the Server. Cookies might contain information such as login or registration information, online “shopping cart” information, user preferences, etc.

COM port - Short for a serial communication port. Most DNC software communicate with a computer through a communication port, and most IBM and IBM-compatible computers support up to four serial ports COM1, COM2, COM3 and COM4. Additional ports can be added by adding additional hardware.

CRP - Acronym for Capacity Requirement Planning. This is a subset of MRP II that enables manufacturers to plan and schedule equipment use and production.`

D

Data bits - A group of bits (1's and 0's) that represent a single character or byte. Typically, there are seven or eight data bits. During an asynchronous communication (e.g., BitCom connecting to CompuServe), each side must agree on the number of data bits. Data bits are preceded by a start bit and followed by an optional parity bit and one or more stop bits.

DDE - An abbreviation of Dynamic Data Exchange. DDE lets two or more programs that support DDE exchange information and commands while they are running.

DNC - Acronym that can mean Distributed Numerical Control or Direct Numerical Control depending upon the application. In the beginning DNC stood for Direct Numerical Control. A computer provided machine instructions for a NC milling machine that were transmitted over telephone lines. Later the term DNC evolved to mean a system where a group of CNC machines are linked to a central computer. Or conversely a combination of computers are each linked to one or more CNC machines and the computers are linked together by way of a local area network. Distributed Numerical Control where by NC programs are sent (distributed) to the memory of a CNC machine. The program is then run from the CNC memory.

Domain Name - The unique name that identifies an Internet site. Domain Names always have 2 or more parts, separated by dots. The part on the left is the most specific, and the part on the right is the most general. A given machine may have more than one Domain Name but a given Domain Name points to only one machine.

Download - To receive one or more files from a remote computer system, such as a computer sending an NC program to a CNC machine. This can also be files received by a computer from a remote computer system, such as another PC or an online service or the internet.

DSL - (Digital Subscriber Line) -- A method for moving data over regular phone lines. A DSL circuit is much faster than a regular phone connection, and the wires coming into the subscriber’s premises are the same (copper) wires used for regular phone service. A DSL circuit must be configured to connect two specific locations, similar to a leased line.

E

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EIA - Format is an older data format used by many older machine tools, teletypes etc. it uses the 7 bit data size, with the eight bit used for error checking. The parity is normally ODD under the ISO format. When EIA format is selected, the information is run through conversion tables to change it to standard ASCII before being saved to disk. On output your ASCII files are converted to EIA format before being transmitted.

Ethernet - A very common method of networking computers in a LAN. Ethernet will handle about 10,000,000 bits-per-second and can be used with almost any kind of computer.

F

Flow control - A method of controlling the amount of data that two devices exchange. In data communications, flow control prevents one modem from "flooding" the other with data. If data comes in faster than it can be processed, the receiving side stores the data in a buffer. When the buffer is nearly full, the receiving side signals the sending side to stop until the buffer has space again. Between hardware (such as your modem and your computer), hardware flow control is used; between modems, software flow control is used.

FTP - Refers to the File Transfer Protocol, one of the protocols within the TCP/IP protocol group used on the Internet. The FTP Protocol makes it possible to transfer files from one computer (or host) on the Internet to another. A very common use of is to use the FTP program to transfer files from one host to another. FTP is also used frequently to upload files up to a web host for use on the Internet. In manufacturing, FTP is starting to be as a protocol for DNC file transfers. See also Anonymous FTP.

G

Gateway - The technical meaning is a hardware or software set-up that translates between two dissimilar protocols, for example Prodigy has a gateway that translates between its internal, proprietary e-mail format and Internet e-mail format. Another, sloppier meaning of gateway is to describe any mechanism for providing access to another system, e.g. AOL might be called a gateway to the Internet.

GIF - (Graphic Interchange Format) -- A common format for image files, especially suitable for images containing large areas of the same color. GIF format files of simple images are often smaller than the same file would be if stored in JPEG format, but GIF format does not store photographic images as well as JPEG.

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H

Handshaking - Is the way in which the data flow between computers/hardware is regulated and controlled. Two distinct kinds of handshaking are described: Software Handshaking and Hardware Handshaking. An important distinction between the kinds of signals of the interface is between data signals and control signals. Data signals are simply the pins which actually transmit and receive the characters, while control signals are everything else.

Host - Any computer on a network that is a repository for services available to other computers on the network.

HTML - (HyperText Markup Language) is the coding language used to create Hypertext documents for use on the World Wide Web. HTML looks a lot like word processing codes, where you surround a block of text with codes that indicate how it should appear. In addition, in HTML you can specify that a block of text, or a word, is linked to another file on the Internet. HTML files are meant to be viewed using a World Wide Web Client Program, such as Netscape or Explorer.

HTTP- (Hypertext Transfer Protocol) The Hypertext Transfer Protocol (HTTP) is the set of rules for exchanging files (text, graphic images, sound, video, and other multimedia files) on the World Wide Web. Relative to the TCP/IP suite of protocols (which are the basis for information exchange on the Internet), HTTP is an application protocol.

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I

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ISO - Format is the most widely used data format for NC machines. it uses the 7 bit data size, with the eight bit used for error checking. The parity is normally EVEN under the ISO format. This also called even parity ASCII.

I/O address - An abbreviation for input/output address. Your fax modem uses an I/O address, which is a reserved space in your computer's input/output address space.

IP address - is used by TCP/IP (the Internet) to route data between computers. Each computer and machine has a 32 bit IP address, which can be related to a simple name such as the name of this website. IP addressing allows packets of information to get to their destinations because every network device on the Internet has a unique, numeric address. These numbers are called IP addresses. An IP address usually looks something like this "243.255.255.12" See TCP/IP

J

Java - Is a network-oriented programming language invented by Sun Microsystems that is specifically designed for writing programs that can be safely downloaded to your computer through the Internet and immediately run without fear of viruses or other harm to your computer or files. Using small Java programs (called "Applets"), Web pages can include functions such as animations, calculators, and other fancy tricks.

JPEG - Stands for Joint Photographic Experts Group and is most commonly mentioned as a format for image files. JPEG format is preferred to the GIF format for photographic images as opposed to line art or simple logo art.

Jumper - A small plug or switch that lets you customize a circuit board. For example, most internal modems let you change their COM port by changing a jumper switch.

K

Kermit - is a file transfer protocol first developed at Columbia University in New York City in 1981 for the specific purpose of transferring text and binary files without errors between diverse types of computers over potentially hostile communication links. It is sometimes used in CNC communications.

Kilobyte - A thousand bytes. Actually, usually 1024 (2^10) bytes.

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L

LAN - (Local Area Network) -- A computer network limited to the immediate area, usually the same building or floor of a building. See Also: Ethernet

M

Megabyte - A million bytes. Actually, technically, 1024 kilobytes.

MIME - Stands for Multipurpose Internet Mail Extensions. This is a standard for attaching non-text files to standard Internet mail messages. Non-text files can include graphics, spreadsheets, formatted word-processor documents, sound files, etc.

Modem - An abbreviation for MOdulator/DEModulator, a device that lets computers exchange information over a standard telephone line. Computers process information in 1's and 0's called bits. A modem takes these bits from a computer and modulates them into high and low signals that a telephone line can carry. The receiving modem then demodulates them back into 1's and 0's, which the receiving computer can understand.

MRP - Manufacturing Resource Planning - An automated software system for handling information directly related to manufacturing, including bills of material, inventory and orders from purchasing.

MRP II - Manufacturing Resource Planning II - An expanded version of MRP that includes an enhanced capability for planning and scheduling the use of all manufacturing resources. See also CRP

N

NC - Numerical Control The operation of a machine by a series of coded instruction's that consist of numbers and letters of the alphabet and other symbols.  These are translated into pulses of electrical current or other output signals that active motors and other device to run the machine. On early NC machines these signals was often delivered to the machines by using punched tape.  Also, the term NC machine refers to machine tools that do not have a computer and memory installed.  see also CNC

Network - Any time you connect 2 or more computers together so that they can share resources, you have a computer network.

Node - Any single computer connected to a network.

O

OCR - An abbreviation of Optical Character Recognition, a process of recognizing the graphical representations of text and translating it into a format that a word processor can read.

Online - In data communications, a successful connection with a remote computer.

P

Packet Switching - The method used to move data around on the Internet. In packet switching, all the data coming out of a machine is broken up into chunks, each chunk has the IP address of where it came from and where it is going. This enables chunks of data from many different sources to co-mingle on the same lines, and be sorted and directed to different routes by special machines along the way. This allows multiple users to access the same lines at the same time.

PPP - Stands for Point to Point Protocol This is a protocol that allows a computer to use a regular telephone line and a modem to make TCP/IP connections to be on the Internet.

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Padding - Some fax machines and modems expect a certain amount of data for each fax scan line. If a scan line has little or no data, Transmit Fax can, if required, automatically insert "filler" or padding characters (0's) so each scan line is a predefined length. Generally, the newer fax machines and modems do not require padding.

Parity - In data communications, parity is a simple procedure of checking the integrity of transmitted data. The most common type of parity is Even, in which the number of 1's in a byte of data add up to an even number, and None, in which a parity bit is not added.

PCX - A popular bitmap graphic format. PCX is a single page format, so you can convert only one fax page at a time. The DCX format, a multi-page version of PCX, was created to overcome this limitation.

Print driver - A print driver is a program that acts as a translator between your application and your printer. Each printer has its own internal "language" with its own codes and commands. Applications use print drivers to communicate with a variety of printers. In the Windows environment, print drivers are shared, eliminating the need for each application to have its own.

Protocol - A set of rules and conventions to ensure that two modems exchange data without errors. Both sides must use the same protocol. Protocols exist at several levels in a telecommunication connection. There are hardware telephone protocols. There are protocols between the end points in communicating programs within the same computer or at different locations. Both end points must recognize and observe the protocol. Xmodem, Zmodem, Kermit

There is a comprehensive Protocol Directory. http://www.protocols.com/pbook/index.htm

PUNCH- CNC output device - used in CNC machines to output programs to perforated tape. Units can be parallel to tape punch or serial output.

Q

R

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Router - A special-purpose computer hardware device (or software package) that handles the connection between 2 or more networks.

RAM - An acronym for Random Access Memory. RAM is your computer's primary memory, where program instructions and data are stored. Some programs, such as AnyFax OCR, require a certain amount of RAM to run.

Resolution - A measurement of the sharpness or clarity of an image. For printers, resolution is expressed as the number of dots per inch (dpi) displayed horizontally and vertically. Most laser printers can print 300 by 300 dots per inch as a minimum.

RS244 - see EIA an early character set used in numerical control machines

RS358 - A newer character set used by CNC machines, also know as ISO.  Identifying feature is that all characters have even parity.

RS232, RS423, RS422 AND RS485 - The Electronics Industry Association (EIA) has produced standards for RS232, RS423, RS422, and RS485 that deal with data communications. EIA standards where previously marked with the prefix "RS" to indicate the recommended standard. Presently, the standards are now generally indicated as "EIA" standards to identify the standards organization.

Electronic data communications will generally fall into two broad categories: single-ended and differential. RS232 (single-ended) was introduced in 1962. RS232 has remained widely used, especially with CNC control builders. The specification allows for data transmission from one transmitter to one receiver at relatively slow data rates (up to 20K bits/second) and short distances (up to 50' @ the maximum data rate). This 50' limitation can usually be exceeded to distances of 200' or more by using low capacitance cable and keeping the data rates down to 9600 baud and lower.

RS423 is another single ended specification with enhanced operation over RS232; however, it has not been widely used.

When communicating at high data rates, or over long distances, single-ended methods such as RS232 are often inadequate. Differential data transmission (balanced differential signal) offers superior performance. Differential signals can help nullify the effects of ground shifts and induced noise signals that can appear as common mode voltages on a network. RS422 (differential) was designed for greater distances and higher Baud rates than RS232. In its simplest form, a pair of converters from RS232 to RS422 (and back again) can be used. Data rates of up to 100K bits / second and distances up to 4000 Ft. can be accommodated with RS422. RS232 to RS422 converters are commonly used with DNC systems to extend the distance between the DNC computer and the machine tool. Some CNC machine controls also offer RS422 as an alternative to RS232.

RS485 meets the requirements for a truly multi-point communications network, and the standard specifies up to 32 drivers and 32 receivers on a single (2-wire) bus. Also, RS485 drivers are able to withstand "data collisions" (bus contention) problems and bus fault conditions. RS485 is not commonly found in CNC machine controls as a serial data communications method.

SUMMARY OF "RS"

RTS/CTS Hardware handshaking - uses additional wires to tell a sending device when to stop or start sending data. DTR and RTS refer to these Hardware handshaking lines. you can select whether you need to use DTR or RTS individually, or use both lines for hardware handshaking. See also Xon/Xoff

S

SQL - Stands for Structured Query Language which is a programming language for sending queries to databases. Most database applications can now be addressed using SQL. Each specific application will have its own version of SQL implementing features unique to that application, but all SQL-capable databases support a common subset of SQL.

SSL - Stands for Secure Sockets Layer which is a special protocol designed by Netscape Communications to enable encrypted, authenticated communications across the Internet.

Start bit - The starting bit of a byte (or character). In data communications, every byte has a starting bit.

Stop bits - In data communication, one or two bits used to mark the end of a byte (or character). At least one stop bit is always sent.

Swap file - A hidden file of your hard disk or network disk that Windows uses for swapping information from your disk into memory.

T

T-1 Line - A leased-line connection capable of carrying data at 1,544,000 bits-per-second.

T-3 Line - A leased-line connection capable of carrying data at 44,736,000 bits-per-second.

TCP - TRANSMISSION CONTROL PROTOCOL

Telnet - A program that is used to login from one Internet site to another. The telnet program gets you to the login: prompt of another host.

Terabyte - 1000 gigabytes.

Terminal - A device or software program that allows you to send commands to a computer somewhere else. This can be only a keyboard and a display screen. In DNC applications this is a screen in software that emulates a physical terminal and allows you to type commands to a computer or CNC machine. With a terminal you can see all the characters that are being sent and received. This is very useful in establishing initial communications with CNC machines.

Thumbnail -A small bitmap image that lets you preview a file before opening or importing it.

Trojan Horse - is a computer program where the programmer intends that does something undocumented that the programmer intended, but that some users would not approve of if they knew about it. According to some people, a virus is a particular case of a Trojan Horse, namely one which is able to spread to other programs (i.e., it turns them into Trojans too). According to others, a virus that does not do any deliberate damage (other than merely replicating) is not a Trojan. Finally, despite the definitions, many people use the term "Trojan" to refer only to non-replicating malware, so that the set of Trojans and the set of viruses are disjoint.

Terminal emulation - A technique of making a computer act as if it were a particular type of terminal, such as ANSI or VT100. This is useful in see the actual data that is being sent and received during serial communications..

Toolbar - A strip of command buttons, displayed just below the menu bar, to give you quick access to commonly used commands and utilities.

TCP/IP - is want makes the Internet run. The term TCP/IP, which stands for Transmission Control Protocol/Internet Protocol, actually refers to a whole family of protocols, of which TCP and IP are just two. see also IP Address

U

UNIX - A computer operating system (the basic software running on a computer, underneath things like word processors and spreadsheets). UNIX is designed to be used by many people at the same time (it is multi-user) and has TCP/IP built-in. It is the most common operating system for servers on the Internet.

URL - Stands for Uniform Resource Locator which is the normal method of giving the address of any resource on the Internet that is part of the World Wide Web (WWW).

A URL to this document looks like this: http://www.digitek-asi.com/glossary.html

UART - The acronym for Universal Asynchronous Receiver/Transmitter. A UART is a chip that processes the data that goes through your modem. If you are using fax/voice modem, you should use a 16550 or 16550A UART to help ensure clear voice messages.

Upload - To send one or more files from your computer's disk storage to a remote computer. In DNC this usually means from the CNC machine's control back to the DNC computer. This can also mean from your computer's disk to a remote computer, such as another PC or an online service or the internet.

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V

Virus, Computer - A computer virus is usually defined as a self-replicating program that spreads by making copies of itself. These copies can "infect" other programs causing them to do things that the programmer didn't intend. Computer viruses can cause entire hard disks or even computer networks to be corrupted. Sometimes the only cure is complete reformatting of the infected hard drives. Or a virus can just cause message or graphics to harmlessly appear.

Also see WORM and TROJAN HORSE

This is just a basic overview of what viruses are. To avoid all problems associated with viruses, it is better to plan for their detection and elimination, rather then try to figure out what to do about a virus after infection.

Our tips on how to stay virus-free:

VPN - Stands for Virtual Private Network this refers to a network in which some of the parts are connected using the public Internet, but the data sent across the Internet is encrypted, so the entire network is virtually private. An example might be a company network where there are offices in different cities. Using the Internet the offices merge their networks into one network. The data is encrypted to insure that only the offices can see the data on the Internet link.

Virtual memory - A portion of your hard disk that Windows uses as if it were actual memory.

W

WAN - Stands for Wide Area Network which is a network (or Internet) that covers an area larger than a single building or group of buildings.

WORM - is a self-contained computer program, or programs, that is able to spread functional copies of itself to other computer systems (usually via network connections). Unlike viruses, worms do not need to attach themselves to a host program to do damage. There are two basic types of worms--host computer worms and network worms.

NETWORK WORMS consist of multiple parts which are called "segments". Each segment can run on different machines, possibly doing different things. Network Worms use the network to send segments from one machine to another. Network worms that have one main segment which coordinates the work of the other segments are sometimes called an"octopus."

Wave file - A sound file used by Windows. Wave files have the extension .WAV. Your system needs a sound card or a special PC speaker driver to play wave files.

X

Xmodem - is an error-correcting protocol for modems that was created in 1978 by Ward Christensen. It has become a standard. Modems that agree on using the Xmodem protocol send data in 128-byte blocks. If a block is received successfully, a positive (ACK) acknowledgement is returned. If an error is detected, a negative (NAK) acknowledgement is returned and the block is resent. Xmodem uses the checksum method of error checking.

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Xon/Xoff Flow Control - Uses the Xon/Xoff characters to tell the sending device to start and stop sending information. When a receiving device's buffer is nearly full, it will transmit an Xoff character to the sending device. The sending device will stop sending characters until the receiving device sends an Xon character. Xon is normally ASCII value decimal 17 and Xoff is normally ASCII decimal value 19. See also RTS/CTS

Y

Z

Zmodem - is an error-correcting protocol for modems. Modems that agree on using the Zmodem protocol send data in 512-byte blocks. If a block arrives and an error is detected, a "NAK" (negative acknowledgement) is returned and the block is resent.

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Digitek Automation Systems, Inc.
Page was last modified:  03/05/2004 04:27:50 PM