Galil DMC-1800, DMC-1700 user manual Executing Programs Multitasking, XQ #A, n, HX n

‘BOTTOM LINE CR 1500,270,-180

‘HALF CIRCLE MOTION VP 0,3000

‘TOP LINE

CR 1500,90,-180

‘HALF CIRCLE MOTION VE

‘END VECTOR SEQUENCE BGS

‘BEGIN SEQUENCE MOTION EN

‘END OF PROGRAM

Note: The NO command is an actual controller command. Therefore, inclusion of the NO commands will require process time by the controller.

Executing Programs - Multitasking

The DMC-1700/1800 can run up to 8 independent programs simultaneously. These programs are called threads and are numbered 0 through 7, where 0 is the main thread. Multitasking is useful for executing independent operations such as PLC functions that occur independently of motion.

The main thread differs from the others in the following ways:

1.Only the main thread, thread 0, may use the input command, IN.

2.When input interrupts are implemented for limit switches, position errors or command errors, the subroutines are executed as thread 0.

To begin execution of the various programs, use the following instruction:

XQ #A, n

Where n indicates the thread number. To halt the execution of any thread, use the instruction

HX n

where n is the thread number.

Note that both the XQ and HX commands can be performed by an executing program. The example below produces a waveform on Output 1 independent of a move.

#TASK1	Task1 label
AT0	Initialize reference time
CB1	Clear Output 1
#LOOP1	Loop1 label
AT 10	Wait 10 msec from reference time
SB1	Set Output 1
AT -40	Wait 40 msec from reference time, then initialize reference
CB1	Clear Output 1
JP #LOOP1	Repeat Loop1
#TASK2	Task2 label
XQ #TASK1,1	Execute Task1
#LOOP2	Loop2 label

138 • Chapter 7 Application Programming DMC-1700/1800