Control Techniques UD70, User Manual

Page: 32 / 154

UD70
Issue code: 70nu2
4-10 DPL programming
Key to the diagram
BACKGROUND task giving way to the CLOCK task
1
The
BACKGROUND
task waits while the
CLOCK
task runs, and is then
interrupted at the next
CLOCK
task.
2
The
BACKGROUND
task continues running until next interrupted by the
CLOCK
task.
3
The
BACKGROUND
task ends.
BACKGROUND task giving way to the ENCODER and CLOCK tasks
4 ENCODER
and
CLOCK
timing periods begin.
5
The
CLOCK
task runs until it is interrupted by the next
ENCODER
task.
The CLOCK task is completed when the ENCODER task has finished.
6
The
CLOCK
task ends, leaving time for the
BACKGROUND
task to run
until interrupted by the next
ENCODER
task.
7
When the ENCODER task has finished the next CLOCK period has not
arrived. The BACKGROUND task runs until interrupted by the next
CLOCK task.
User-defined sub-routines
User-defined sub-routines are written by the user and are used in
conjunction with the
CALL
instruction (see
CALL
in Chapter 7 Reference).
User-defined sub-routines can be given any name and can be inserted
anywhere in a program. (Note that the task name is case
case-sensitive -sensitive.)
The following sub-routine has the same function as the Sawtooth Sawtooth program
given in Chapter 3 Getting Started. The name given to the sub-routine is
RAMP
::.
BACKGROUND{
Loop:
CALL RAMP:
GOTO Loop:
}
RAMP: {
#1.21=0
DO WHILE #1.21<1000
#1.21=#1.21+1
LOOP
}