PLC Expansion Module USB Interface High-Speed Data Processing
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Solution Overview
Problem
Conventional serial interface methods in medium/large size PLCs result in slow data processing speeds, making it difficult to apply to systems requiring high-speed control, especially when handling massive data processing.
Innovation Solution
The implementation of a USB interface in an expansion module for PLCs, which includes a USB hub, device, input/output sockets, and a controller that allocates exchange numbers and manages signal paths to enhance data processing speed by using a USB signal path and reducing the number of required signal lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional serial interface method is used for PLC expansion modules, then the system is compatible with traditional PLC architecture, but data processing speed is slow and scan time is increased
Solution Approach 1:
The patent changes the communication interface parameter from conventional serial interface to USB interface. The expansion module includes a USB device that communicates with the PLC basic unit's USB host, enabling high-speed data transfer. This parameter change directly resolves the contradiction by improving data processing speed while reducing scan time, as USB communication operates at significantly higher speeds than traditional serial interfaces.
Solution Approach 2:
The patent substitutes the conventional serial communication mechanism with a USB communication mechanism. The expansion module uses a USB device with switching unit to establish USB signal paths, replacing the traditional serial interface method. This substitution enables high-speed control systems to be achieved, directly addressing the speed limitation of conventional serial interfaces.
2Productivity
If USB interface is implemented in expansion module, then data processing speed is significantly improved, but device complexity increases due to additional USB hub, switching unit, and controller components
Solution Approach 1:
The patent implements multi-functionality by integrating a USB hub and switching unit within the expansion module. The switching unit can dynamically connect different pairs among input sockets, output sockets, USB hub sockets, and USB device sockets, allowing a single USB interface to handle multiple communication functions. This reduces the need for separate dedicated signal lines for each function, thereby improving productivity while managing device complexity.
Solution Approach 2:
The patent employs dynamic connection management through the switching unit, which can reconfigure signal paths based on communication needs. The controller dynamically controls the switching unit to establish appropriate USB signal paths during initialization and operation. This dynamic reconfiguration allows the system to adapt to different communication requirements without requiring fixed, complex wiring for all possible scenarios, thus improving productivity while keeping the device complexity manageable.
3Reliability
If conventional serial interface is used, then initialization process is simple with sequential trigger signal allocation, but interface time is consumed when multiple expansion modules require massive data processing
Solution Approach 1:
The patent enables continuous high-speed data transmission through the USB interface. Unlike sequential serial communication, the USB interface allows multiple expansion modules to transmit massive data simultaneously or in rapid succession without significant interface time consumption. The controller manages multiple USB devices connected through the USB hub, maintaining continuous useful action for data processing while ensuring reliable transmission through USB's inherent error handling and retransmission capabilities.
Data Source
AI summary
An expansion module for a PLC, used in such a manner that at least one expansion module is sequentially connected to a basic unit in order to exchange massive data at high speed by using USB communication, is provided. Each of the expansion module includes a USB hub and a USB device, and is allocated with an exchange number from a USB host of the basic unit by activating the USB device according to input of a trigger signal. In addition, whether the USB hub is to be used is determined by deciding whether the expansion through the USB hub is required according to the allocated exchange number. Thus, a user needs only to arrange each of the expansion modules by a designation.