Chapter 5 Program Configuration and Operation Method
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(e) Protection of Program in execution from Task Program
1) In case that the continuity of program execution is interrupted by high priority Task Program during
program execution, it is available to prohibit the execution of Task Program partially for the part in
problem. In this case, it is available to perform the program protection by „ DI (Task Program Start
Disabled) and „EI (Task Program Start Enabled)‟ application instruction.
2) Insert „DI‟ application instruction in the start position of the part requiring the protection and insert „EI‟
application instruction in the position to release. Initialization Task is not influenced by „DI‟, „EI‟
application instruction.
3) If interrupt is occurred while „CALLP‟ instruction executing, interrupt program is executed after „CALLP‟
instruction execution.
(5) Cyclic task program processing method
Here describes the processing method in case that task (start condition) of Task program is set as Cycle
time.
(a) Items to be set in Task
Set the execution cycle and priority which are the start condition o f Task program to execution. Check the
task no. to manage the task.
(b) Cyclic task processing
Performance the corresponding cyclic task program per setting time interval (execution cycle).
(c) Notice in using cyclic task program
1) When cyclic task program is in execution currently or waiting for execution, if the demand to execute the
same task program occurs, the new occurred task shall be disregarded.
2) Timer that makes a demand to execute cyclic task program only while operation mode is Run mode,
shall be added. The shutdown time shall be all disregarded.
3) When setting the execution cycle of cyclic task program, consider the possibility that the demand to
execute several cyclic task program at the same time occurs.
If 4 cyclic task programs that the cycle is 2sec, 4sec, 10sec and 20sec are used, 4 demands of
execution per 20 seconds shall be occurred at the same time and scan time may extend
instantaneously.
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