Galil Motion Control DMC-18 2 Series, Руководство пользователя

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124 ● Chapter 7 Application Programming DMC-18x2
Example:
An example of a subroutine to draw a square 500 counts per side is given below. The square is drawn
at vector position 1000,1000.
#M Begin Main Program
CB1 Clear Output Bit 1 (pick up pen)
VP 1000,1000;VE;BGS Define vector position; move pen
AMS Wait for after motion trippoint
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;BGX Define X,Y; Begin X
AMX;BGY;AMY After motion on X, Begin Y
EN End subroutine
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-18x2 has a special label for automatic program execution. A program which has been saved
into the controllers non-volatile memory can be automatically executed upon power up or reset by
beginning the program with the label #AUTO. The program must be saved into non-volatile memory
using the command, BP. If you include the #AUTOERR routine in your program and you have a
checksum error, this program will execute. For more information, read the operand section of the RS
command in your command reference.
Automatic Subroutines for Monitoring Conditions
Often it is desirable to monitor certain conditions continuously without tying up the host or DMC-18x2
program sequences. The DMC-18x2 can monitor several important conditions in the background.
These conditions include checking for the occurrence of a limit switch, a defined input, position error,
or a command error. Automatic monitoring is enabled by inserting a special, predefined label in the
applications program. The pre-defined labels are:
SUBROUTINE DESCRIPTION
#LIMSWI Limit switch on any axis goes low
#ININT Input specified by II goes low
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