Subroutines, Stack manipulation, Auto-start routine – Galil DMC-2X00 User Manual

Page 146

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ELSE

ELSE command for 2

nd

IF statement

MG "ONLY INPUT 1 IS ACTIVE

Message executed if 2

nd

IF is false

ENDIF

End of 2

nd

conditional statement

ELSE

ELSE command for 1

st

IF statement

MG"ONLY INPUT 2 IS ACTIVE"

Message executed if 1

st

IF statement

ENDIF

End of 1

st

conditional statement

#WAIT

Label to be used for a loop

JP#WAIT,(@IN[1]=0) | (@IN[2]=0)

Loop until Input 1& 2 are not active

RI0

End Input Interrupt Routine without restoring
trippoints

Subroutines

A subroutine is a group of instructions beginning with a label and ending with an End command (EN).
Subroutines are called from the main program with the jump subroutine instruction JS, followed by a
label or line number, and conditional statement. Up to 8 subroutines can be nested. After the
subroutine is executed, the program sequencer returns to the program location where the subroutine
was called unless the subroutine stack is manipulated as described in the following section.

An example of a subroutine to draw a square of 500 counts per side is given below. The square is
drawn at vector position 1000, 1000.

Stack Manipulation

It is possible to manipulate the subroutine stack by using the ZS command. Every time a JS
instruction, interrupt or automatic routine (such as #POSERR or #LIMSWI) is executed, the subroutine
stack is incremented by 1. Normally the stack is restored with an EN instruction. Occasionally it is
desirable not to return back to the program line where the subroutine or interrupt was called. The ZS1
command clears 1 level of the stack. This allows the program sequencer to continue to the next line.
The ZS0 command resets the stack to its initial value. For example, if a limit occurs and the #LIMSWI
routine is executed, it is often desirable to restart the program sequence instead of returning to the
location where the limit occurred. To do this, give a ZS command at the end of the #LIMSWI routine.

Auto-Start Routine

The DMC-2x00 has a special label for automatic program execution. A program which has been saved
into the controller’s non-volatile memory can be automatically executed upon power up or reset by

Instruction Interpretation

#M

Begin Main Program

CB1

Clear Output Bit 1 (pick up pen)

VP 1000,1000;LE;BGS

Define vector position; move pen

AMS

Wait for after motion trip point

SB1

Set Output Bit 1 (put down pen)

JS #SQUARE;CB1

Jump to SQUARE subroutine

EN

End Main Program

# SQUARE

SQUARE subroutine

v1=500;JS #L

Define length of side

v1=-v1;JS #L

Switch direction

EN End

subroutine

#L;PR v1,v1;BGA

Define A,B; Begin A

AMA;BGB;AMB

After motion on A, Begin B

EN End

subroutine

136

Chapter 7 Application Programming

DMC-2X00

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