Switch..case—program branching, 35 conditional bloc k run – HEIDENHAIN CNC Pilot 4290 V7.1 User Manual

Page 324

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324

4.35 Conditional Bloc

k Run

SWITCH..CASE—program branching

The switch statement consists of the elements:

„

SWITCH, followed by a variable. The content of the variables is
interrogated in the following CASE instruction.

„

CASE x: The CASE branch is run with the variable value x. CASE can
be programmed repeated times.

„

DEFAULT: This branch is executed if no CASE instruction matched
the variable value. DEFAULT can be omitted.

„

BREAK: Concludes the CASE branch or DEFAULT branch

Programming:

U

Select “Instr. > DIN PLUS words” in the machining menu. The CNC
PILOT opens the “DIN PLUS words” selection list.

U

Select SWITCH

U

Enter the switch variable

U

For each CASE branch:

„

Select CASE (from the DIN PLUS words selection list)

„

Enter the SWITCH condition (value of the variable) and
insert the NC blocks to be executed.

U

For the DEFAULT branch: Insert the NC blocks to be executed.

V variables are included during simulation. The V variables can be
assigned values. Thus all branches of your NC program can be tested.

Example for V variables

Relational operators

<

Less than

<=

Less or equal

<>

Not equal to

>

Greater than

>=

Greater than or equal

==

Equal

Combining conditions:

AND

Logical AND operation

OR

Logical OR operation

„

You can combine up to two conditions.

„

If the branch is triggered by V variables or events, the
contour follow-up is switched off with the SWITCH
statement and back on with the ENDSWITCH
statement. With G702, G703 or G706 you control the
contour follow-up.

. . .

N.. SWITCH{V1}

N..

CASE 1

[EXECUTED IF V1=1]

Executed if V1=1

N.. G0

XI10

. . .

N..

BREAK

N..

CASE 2

[EXECUTED IF V1=2]

Executed if V1=2

N.. G0

XI20

. . .

N..

BREAK

N..

DEFAULT

No CASE instruction matched the variable value

N.. G0

XI30

. . .

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