PLC Control Program Allocation Based on Delay and Resource Limits

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In factory automation systems, the Programmable Logic Controllers (PLCs) that execute control programs are typically fixed, limiting the flexibility to freely dispose control programs among multiple PLCs.

Innovation Solution

A control system that includes a network-connected control target and multiple devices, each with program storage, an execution module, and a disposition module. The disposition module determines the optimal device for disposing control programs based on communication delay time and resource information such as storage area size and processor availability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If control programs are fixed to specific PLCs, then system stability is maintained, but flexibility to freely dispose control programs among multiple PLCs is limited

Engineering Contradiction:

Improveflexibility to dispose control programsVSAvoidsystem complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic assignment of control programs to PLCs based on real-time communication delay measurements. The disposition module can reassign control programs between PLCs adaptively, transforming the static PLC assignment into a dynamic system that responds to changing communication conditions, thereby improving flexibility without excessive complexity

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the parameter of PLC assignment from fixed to variable based on communication delay time. By measuring communication delays and using this data to determine optimal PLC assignments, the system dynamically adjusts the disposition of control programs to achieve better performance while maintaining manageable complexity through automated decision-making

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If control programs are freely disposed among multiple devices, then flexibility is improved, but determination of optimal device becomes complex

Engineering Contradiction:

Improveflexibility to dispose control programsVSAvoiddifficulty in determining optimal device

Core Design Contradiction:

Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The system uses self-service by having PLCs automatically measure their own communication delay times and report them to the disposition module. Each PLC independently evaluates its own communication performance with other devices, eliminating the need for complex external measurement systems and simplifying the determination process while enabling flexible program disposition

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The disposition module receives feedback in the form of communication delay time measurements from PLCs and uses this information to determine optimal program assignments. This feedback mechanism transforms the complex decision-making process into an automated system that continuously optimizes PLC disposition based on actual communication performance data

Inventive Principle:

Principle #23Feedback

3Speed

If communication delay time is minimized, then execution speed is improved, but device selection becomes more restrictive

Engineering Contradiction:

Improvecommunication speedVSAvoiddevice selection flexibility

Core Design Contradiction:

SpeedVSAdaptability or versatility

Solution Approach 1:

The system measures communication delay times between all PLC pairs (excessive action) but uses this comprehensive data to make selective assignments. By gathering more communication data than strictly necessary, the system ensures that optimal assignments can be made even when device selection becomes restrictive, maintaining both speed optimization and assignment flexibility

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS12276958B2Control system, setting device, and computer-readable storage medium

Publication Date: 2025.04.15 OMRON CORP

AI summary

A control system includes a control target and plural devices, and the control target and the devices are connected to a network. The control system includes a program storage provided in each device storing a control program that calculates control data using data exchanged with the control target, an execution module and a disposition module. The execution module is included in each device and causes a processor to execute programs including a disposed control program. The disposition module disposes control programs in one or more of the devices. The disposition module determines a device in which the control program is disposed from among the plural devices based on a communication delay time between the devices and information about a resource usable for execution of the control program of each device for each control program.