Datasheet

CJ1 series CPU Units 163
Programmable
Controllers
Better Design/Development Efficiency
Structured Programming and Team Program Development Using Tasks
With CJ-series PLCs, programs can be divided into programming units
called tasks. There are both cyclic tasks, which are executed each
cycle in a specified order, and interrupt tasks, which are executed
when an interrupt occurs.
With CJ1-series PLCs, up to 288 tasks can be executed as cyclic
tasks.
Task Programming Example with CX-Programmer
Advantages
Program Standardization
Task programs are created in units divided by functionally by purpose.
These functional units can be easily reused when programming new
PLCs or systems with the same functionality.
Easier-to-understand Programs
With scroll-like programs, individual functional units are extremely diffi-
cult to find just by looking at the program.
Tasks are used to separate a program functionally and make the pro-
gram much easier to understand.
Shorter Cycle Times
With a scroll-like program, many jump and similar instructions had to
be used to avoid executing specific parts of the program. This not only
slows down the programs, but makes them more difficult to under-
stand. With task programming, special instructions enable controlling
the execution of tasks so that only the require tasks are executed dur-
ing any particular cycle.
Control
method
PID control method PID with 2 degrees of freedom (with autotuning)
Control combinations Any of the following function blocks can be combined:
Basic PID control, cascade control, feed-forward control, sample PI control, Smith dead time
compensation control, PID control with differential gap, override control, program control, time-
proportional control, etc.
Alarms PID block internal alarms 4 PV alarms (upper upper-limit, upper limit, lower limit, lower lower-limit) and 1 deviation alarm
per PID block.
Alarm blocks High/low alarm blocks, deviation alarm blocks
Task Programming
Item Model CJ1G-CPU42P CJ1G-CPU43P CJ1G-CPU44P CJ1G-CPU45P
Tasks
Program A
Program B
Cyclic
task 0
Cyclic
task 1
Cyclic
task n
Interrupt
task
Allocation
Allocation
Task types (cyclic or
interrupt) and task
numbers are set in
the project tree.
Programs can be separated into tasks
like “card-style programs” to make them
easier to understand.
Starting tasks at startup is set
in cyclic task 0 (the overall
control task) using the TASK
ON (TKON(820)) and TASK
OFF (TKOF(821)) instructions.
Standard Programming Units
Program ABC
Program A
Program B
Program C
Program ABD
Program A
Program B
Program D
Scroll-like programs Tasks
TKOF
A
Wait
Y201-EN2-03.book Seite 163 Donnerstag, 30. März 2006 1:52 13