Industrial Control Data Transfer Switching Between PIO and DMA
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Solution Overview
Problem
Existing transfer systems for communication data in industrial control devices, such as the DMA system, often result in longer transmission times that depend on the data amount, necessitating a method to select an optimum transfer system based on data size.
Innovation Solution
A control system that includes a computation processing unit capable of selecting between a PIO system and a DMA system for transferring communication data, measuring and comparing transfer times, and choosing the system with the shorter average transfer time and lower variation to ensure timely and consistent data transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the DMA system is used to transfer communication data, then the transfer speed is improved, but the transfer time increases when the data amount is large
Solution Approach 1:
The patent implements dynamic selection between PIO and DMA transfer systems based on real-time data amount conditions. The computation processing unit automatically switches transfer modes: using PIO for small data amounts and DMA for large data amounts, thereby optimizing both transfer speed and time efficiency across different operational scenarios
Solution Approach 2:
The patent changes the transfer system parameter (PIO vs DMA) based on the data amount parameter. By monitoring the data amount and adjusting the transfer system selection accordingly, the system achieves optimal transfer performance - using PIO for small data and DMA for large data, resolving the contradiction between transfer speed and transfer time
2Loss of time
If the PIO system is used to transfer communication data, then the transfer time is reduced for small data amounts, but the transfer speed is slower compared to DMA system
Solution Approach 1:
The system dynamically adjusts the transfer mode based on data amount conditions. For small data amounts, PIO is selected to minimize transfer time; for large data amounts, DMA is selected to maximize transfer speed. This dynamic adaptation resolves the speed-time contradiction across different data scenarios
Solution Approach 2:
The transfer system parameter is changed based on the data amount parameter. The computation processing unit selects PIO or DMA by evaluating the data amount condition, thereby optimizing the balance between transfer time and transfer speed for different data sizes
3Device complexity
If a fixed transfer system is used, then the system complexity is reduced, but the adaptability to different data amounts is worsened
Solution Approach 1:
The control device is designed with multi-functionality, supporting both PIO and DMA transfer systems within a single device. The computation processing unit can selectively activate either transfer mode based on data amount conditions, providing universal adaptability without requiring separate dedicated systems for different data sizes
Solution Approach 2:
The system dynamically selects between PIO and DMA transfer modes based on real-time data amount conditions. This dynamic adaptability allows the fixed hardware architecture to respond flexibly to varying data sizes, maintaining low system complexity while achieving high adaptability
Data Source
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AI summary
A control system includes one or a plurality of functional units, and a control device for exchanging communication data transmitted circularly among the functional units. The control device selects, in accordance with an instruction from a user or in accordance with a predetermined condition, one transfer system of a first transfer system in which a computation processing unit transfers the communication data and a second transfer system in which a DMA controller transfers the communication data.