Omron NY532-1500 User Manual page 51

Using Motion Control Instructions in Two Different Types of Tasks
If you have processes that require high-speed motion control and processes that do not require high-
speed motion control for the same axis, you can place the motion control instructions (FB) both in the
primary periodic task and in a priority-16 periodic task.
If motion control instructions (FB) are executed in both tasks within the period of the priority-16 periodic
task, the MC Function Module will perform motion processing for instructions in the primary periodic
task first.
For example, the MC_MoveAbsolute instruction is executed in the priority-16 periodic task. Then, the
MC_MoveRelative is executed for the same axis in the primary periodic task. The operation for this is
shown below.
• The MC Function Module will execute MC_MoveRelative first. MC_MoveAbsolute is executed with
multi-execution of instructions.
Primary period
Primary
UPG
IO MC
periodic task
Priority-16
periodic task
The values of output variables for a motion control instruction and the values of system-defined vari-
ables for motion control will change during the I/O refresh of the task that executed the instruction.
Therefore, you may notice different behavior depending on the task if you use motion control instruc-
tions for the same axis in different tasks. Make sure that you thoroughly understand the processes of
each task before you start to develop your user program.
Precautions for Correct Use Precautions for Correct Use
• If you include motion control instructions for the same axis in both the primary periodic task
and the priority-16 periodic task, pay close attention to the following when you develop your
user program: the execution order of the motion control instructions, the timing of updates for
system-defined variables for motion control, and the output timing of command values.
• If you use system-defined variables for motion control for the same axis in multiple tasks, pay
close attention to the differences in timing for updating system-defined variables for motion
control when you develop your user program.
Additional Information
For information on multi-execution of instructions, refer to 9-5-7 Multi-execution of Motion Con-
trol Instructions (Buffer Mode).
NY-series Industrial Panel PC / Industrial Box PC Motion Control User's Manual (W559)
Servo
UPG
IO MC
FB2
FB2: MC_MoveRelative
UPG
FB1
FB1: MC_MoveAbsolute
Task period (primary period × 3)
2 Motion Control Configuration and Principles
Execution command for MC_MoveRelative
UPG UPG
IO MC IO
FB2 FB2
UPG
MC IO MC
FB2
The instruction is buffered for
multi-execution of instructions.
2
2-11