
B–61863E–1/06
2. TASK CONTROL FUNCTION
PMC CONTROL SOFTWARE
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Tasks must be registered with the PMC control software when the PMC
software is created. Up to 16 tasks can be registered.(For the C function
of the Series 16i/18i/21i/15i–A, up to 32 tasks) Registration of a task, as
used here, means specifying user task information called link control
statement data in the user program area. The user task information
consists of the data items shown below.
The link control statement data can be created using the tool dedicated to
creating link control statements. (See IV-4 for details of how to create the
link control statement.)
The physical addresses and the number of user definition GDTs defined
by the user program are specified. Up to 64 user definition GDTs, each
ranging from 32 to 95, can be registered. GDT entries defined by the
builder must be within this range. (For the C function of the Series
16i/18i/21i/15i–A, up to 192 addresses from 32 to 223)
In the user program, when the common memory area (data area) that is
accessed by two or more tasks is used, the number of common memories
and the GDT entry defined by the builder are specified. If there is no
common memory, 0 is specified for the number of common memories.
Task levels of the third-level ladder program can range from 10 to 99.
Level 10 has the highest priority and level 99 has the lowest priority. If
the third ladder level is not provided or it need not be started, 0 is
specified.
Since the third ladder level is started periodically, its start cycle is
specified. The start cycle must range from 8 ms to 2000 ms. If a value
other than multiples of 8 is specified, the value is rounded down to the
nearest multiple of 8.
The number of tasks to be registered by the user program is specified. (Up
to 16 tasks. For the C function of the Series 16i/18i/21i/15i–A, up to 32
tasks)
The tasks in the third-level ladder program are not included.
When each task is activated, the name of the function to be executed first
is specified.
The GDT entry of the data segment to be used by each task is specified.
2.4
REGISTRATION OF
TASKS
2.4.1
Addresses and the
Number of User GDTs
2.4.2
Number of Common
Memories and
Common Memory GDT
Entries
2.4.3
Task Level and Start
Cycle of the Third
Ladder Level
2.4.4
Number of Tasks to be
Registered
2.4.5
Task Entry Address
Name
2.4.6
Task Data Segment
GDT Entry