Ladder Logic ElementsIntermediateImportant
1 min read
Updated 2025-11-10
Intermediate

Return

RET - Return

Exits subroutine and returns control to calling program at next instruction.

Key Takeaways

  • Exits subroutine and returns control to calling program at next instruction.
  • Intermediate-level topic in Ladder Logic Elements
  • Commonly used in: Industrial process control, Machine automation

Detailed Definition

Return is a fundamental ladder logic element or instruction used to implement control logic in PLC programs. Exits subroutine and returns control to calling program at next instruction. This instruction type enables programmers to create specific control behaviors, implement timing functions, or manage data within ladder logic programs. Understanding and properly utilizing Return is essential for developing effective ladder logic programs that meet application requirements.

The implementation of Return follows established conventions and best practices for ladder logic programming. Programmers must consider scan time impacts, proper placement within ladder rungs, and interaction with other instructions when using Return. Common applications include sequential control, state machine implementation, and process interlocking. Effective use of Return contributes to clear, maintainable ladder logic programs that can be easily understood and modified by maintenance personnel.

Why It Matters

Understanding Return is important in PLC programming and industrial automation. This concept plays a vital role in:

  • Industrial process control
  • Machine automation
  • System monitoring and diagnostics
  • Data processing and management

Mastering this important concept will enhance your ability to design, implement, and troubleshoot industrial automation systems effectively.

Real-World Use Cases

Return is applied across various industrial automation scenarios:

Industrial process control

Machine automation

System monitoring and diagnostics

Data processing and management

Practical Examples

Here are real-world examples of how Return is implemented in industrial settings:

1

Using Return in a packaging machine control system for product handling and quality inspection

2

Implementation of Return in HVAC control for optimizing energy consumption and comfort

Pro Tip: These examples demonstrate common implementation patterns. Adapt them to your specific application requirements and PLC platform.

Common Questions

What is Return?

Exits subroutine and returns control to calling program at next instruction.

When should I use Return?

Return is particularly useful in scenarios such as Industrial process control and Machine automation. Consider implementing it when you need reliable, efficient solutions for these types of applications.

What are related concepts I should learn?

To fully understand Return, you should also familiarize yourself with TON (Timer On-Delay), TOF (Timer Off-Delay), and CTU (Count Up). These concepts work together in industrial automation systems.

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Quick Info

Difficulty
Intermediate
Tier
Important

About Ladder Logic Elements

Contacts, coils, timers, counters, and ladder diagram components

Total Terms:70
Difficulty:Beginner to Intermediate