Bradley Smoker PLC-5 Using Processor Input Interrupts, Using a Processor Input Interrupt, 18-1

Chapter 18

Using Processor Input Interrupts

Using This Chapter

For Information About	Go to Page
Using a processor input interrupt	18-1
Defining a processor input interrupt	18-5
Monitoring processor input interrupts	18-5

Using a Processor Input Interrupt

A processor input interrupt (PII) specifies when an event-driven input causes the controller to interrupt program execution and run a PII program file once to completion. Afterwards, the controller resumes executing the program file from where it was interrupted. Use PIIs only for inputs in the controller-resident chassis.

You can use a processor input interrupt (PII) as an event-driven interrupt or in high-speed processing applications. For example, you may need to count inputs quickly to track production, such as in a canning line. Or, use a PII if your application calls for an immediate input update when a part is seen on a conveyor and you need to do an immediate output update to perform the next action. For example, when a part moving down a conveyor line is detected, you may need to stop it so the next piece can be added.

Your PII program can contain immediate update instructions to complete high-speed control functions. As your ladder program is running and the input condition occurs, the controller interrupts program execution and runs the PII program file. Then, the controller resumes executing the program file from the point where it was interrupted.

Publication 1785-UM012D-EN-P - July 2005