Omron CJ2 - 02-2010 User Manual page 119

Example 1: Designing Tasks by Function and Personnel in Charge.
Error processing
Communications
MMI
Initial processing
Main processing
Break down
by function
Example 2: Designing Tasks by Execution Priority
Allocate lower numbers to control tasks than to processing tasks.
• Break down and design programs to ensure autonomy. Keep the amount of data exchanged between
tasks to an absolute minimum.
Organize the I/O memory used by all tasks and the I/O memory used only in individual tasks. Orga-
nize and allocate a range of I/O memory for use only by each task.
Used by All Tasks
Task 0
D20000 to D24999
W200.0 to W299.15
D0 to D19999
D20000 to D24999
D25000 to D29999
D30000 to D31999
D32000 to D32767
• Use one task to start and stop other tasks and thus control the overall user program.
Good Example: Define a master-slave relationship between tasks.
Task
management
(master)
CJ2 CPU Unit Software User's Manual
Conveying
Inspection
Assembly
Machining
Materials supply
Break down
by process
Interrupts
Overall
Input
control
process-
(may
ing
include
error
processing
in some
cases)
Break down by execution and non-execution conditions
D0 to D19999
W0.0 to W199.15
Task 1
D25000 to D29999
W300.0 to W399.15
DM Area
Used by all tasks.
Task 0
Task 1
Task 2
Not used
Task 1 (slave)
Task 2 (slave)
Task 3 (slave)
5 Understanding Programming
Person D
Person C
Person B part 2
Person B part 1
Person A
Break down by
personnel in charge
Break down by function
Output
Error processing
processing
Sequence control
Analog control
Man-machine interfacing
Task 2
D30000 to D31999
W400.0 to W499.15
Work Area
W0.0 to W199.15
Used by all tasks.
W200.0 to W299.15 Task 0
W300.0 to W399.15
Task 1
W400.0 to W499.15
Task 2
W500.0 to W511.15 Not used
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