Chapter 1 Product Introduction task. Function block POUs or function POUs are automatically called by the program POU. There are three types of tasks. 1_ 1. Cyclic task: The program POUs assigned to cyclic tasks are scanned cyclically, and executed in order. 2. Timed interrupt task: If the interrupt time is reached, all program POUs assigned to the timed interrupt task are executed in order. 3. Conditional interrupt task: Conditional Interrupts can be divided into several types, such as external interrupts, and I/O interrupts. You must make sure that the PLC supports the interrupts before you use conditional interrupts in a project.
If you assign a program POU to a conditional interrupt task, the program POU is similar to an interrupt subroutine. When the interrupt condition is satisfied (for example, the contact of the external interrupt is triggered) then all program POUs assigned to the conditional interrupt task are executed in order. 1-11