Question

What is a program format?

CNC programming is based on what current standard?

Briefly describe the Word address format.

Define each of the following as they pertain to CNC programming.Explain G code?

1.Character
2.Address
3.Word
4.Block
5.Program

Explain what a G code is?

The difference between modal and nonmodal G codes?

Explain the mode and use of each of the following G codes.Explain what an M code is.
G 49
G1
G80
G0
G92

Explain what a M code is.

What two main groups to M codes fall?

Explain the type and use of the following M codes.Explain the function of the following Word address command.
M6
M30
M0
M3
M5
Explain the function of the following Word address command.
(N0080 G83 X-.5 Y.375 Z-.8876 R.1 Q.1)

Answer 1

Program Format determines the structure of a Program of Study.

CNC Programming is based on ISO 6983 standard.

Word Address Format
The word address format features an address for each data element to permit the controller to assign data to their correct register in whatever order they are received. A single alpha character (said to be a "word") is used to identify each register. The Electronics Industries Association (EIA) has developed, and the American National Standards Institute (ANSI) has adopted, a standard format for N/C data, ANSI/EIA-274-D. This standard is followed by most N/C equipment manufacturers. EIA-274-D assigns specific letters as address words for the various registers. Most N/C controllers use the address words F, G, I, J, K, M, N, S, T, X, Y, and Z.

1. CHARACTER: The smallest unit in CNC programming is a character. It can be a letter, digit, or a symbol.
2. ADDRESS: The word address format features an address for each data element to permit the controller to assign data to their correct register in whatever order they are received.
3. WORD: Combination of characters is called as Word.
4. BLOCK: Every cnc program is a sequence of many cnc program blocks which are written together to form a complete tool-path for one or many tools.
5. PROGRAM: It is a set of instructions for computers to control a machine tool.

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WHAT IS G-CODE ?
G-code is a programming language for CNC (Computer Numerical Control) machines. G-code stands for “Geometric Code”.

G 49
To use a tool length offset, program G43 H~, where the H number is the desired index in the tool table. It is expected that all entries in this table will be positive. The H number should be, but does not have to be, the same as the slot number of the tool currently in the spindle. It is OK for the H number to be zero; an offset value of zero will be used. Omitting H has the same effect as a zero value.
To use no tool length offset, program G49

G1
For linear motion at feed rate (for cutting or not), program G1 X~ Y~ Z~ A~ B~ C~, where all the axis words are optional, except that at least one must be used. The G1 is optional if the current motion mode is G1.

G80
Program G80 to ensure no axis motion will occur.

G0
For rapid linear motion, program G0 X~ Y~ Z~ A~ B~ C~, where all the axis words are optional, except that at least one must be used. The G0 is optional if the current motion mode is G0.

G92
To make the current point have the coordinates you want (without motion), program
G92 X~ Y~ Z~ A~ B~ C~ , where the axis words contain the axis numbers you want.

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WHAT IS M CODE?
M-code is the machine control language for CNC machining. It is used in combination with G-code to switch various machine functions off and on.

TWO MAIN GROUPS OF M CODE?
1. Lathe Operations
2. Milling Operations

M6
Tool change

M30
End of program (Reset)

M0
Program stop

M3
Spindle start forward CW

M5
Spindle Stop