NC-block structure

A NC-block consists of a block number (optional), a number of words and a block end identification.

The application of special commands (#<Statement>) as described in paragraph 11 excludes the programming of further words in the NC program (except of NC block number).

Generally, each block begins with a block-number, consisting of an N-Character, followed by a mathematical expression. This expression is mapped, in case of respective setting of the decoder, into the display data rounded off as integer.

For program flow the block number is of no significance. Hence it need not be programmed in ascending order.

Example for a block structure:

The NC commands conforming to DIN 66025 must not be compulsorily separated through space characters or tabulators. For programming of text commands deviating from DIN (control statements, special functions, ... ), separating characters are necessary and useful also for structuring a NC-program.

Examples for an NC-program structure:

Without numbering

Partial numbering

Complete numbering

% 100
"Block 1"
"Block 2"
"Block 3"
.
.
.
M30

% 100
N10 "Block 1"
"Block 2"
N20 "Block 3"
"Block 4"
.
.
M30

% 100
N10 "Block 1"
N20 "Block 2"
N30 "Block 3"
N40 "Block 4"
.
.
N700 M30

Words are to be differentiated according to their significance in words with:

• Geometrical information (e.g. positions),
• Technological information (e.g. spindle speed, feedrate, right-handed spindlerotation),
• Information for the control of program sequential flow (so called control blocks like e.g. counting loop),
• Arithmetical information (for instance, calculation of a variable, parameter calculation).

Several words could be in a block (exception: the special commands from chapter 11-Special functions). The sequence of processing the control information within the block is specified through the control. Thus, the individual words of an NC-block can be entered in any desired order by the programmer. The sequence has no effect upon the processing. In cases of exceptions special notes are drawn in this programming manual.

The block end code is firmly given. It can be any control character. Customarily, the control character "CR" is used.