Dual-Controller Field Bus Loopback for Continuous Slave Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In factory automation systems, when a controller fails or is temporarily stopped for firmware rewriting, control for multiple slave devices is interrupted, leading to production defects and reduced productivity.
Innovation Solution
A control system with two controllers connected through a field bus and a data communication network, allowing one controller to generate and transmit control frames while the other performs loopback communication, ensuring continuous control even if one controller fails, and enabling seamless switching between controllers for operation confirmation and redundancy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single controller is used to control multiple slave devices, then the device complexity is reduced, but the reliability deteriorates because control stops when the controller fails or is temporarily stopped
Solution Approach 1:
The system divides the controller function into two separate controller devices (first controller and second controller), each capable of independently controlling the slave devices. This segmentation eliminates the single point of failure while maintaining relatively simple individual controller configurations.
Solution Approach 2:
The system changes the operational state parameters of the controllers by switching between normal operation mode and backup mode. The first controller operates normally while the second controller performs loopback communication, and they can switch roles when needed, maintaining control continuity without increasing permanent system complexity.
2Reliability
If a backup controller is added to ensure continuous control, then the reliability improves, but the device complexity increases
Solution Approach 1:
Both the first controller and second controller are designed with universal functionality to control the same set of slave devices. Each controller has the capability to generate control frames and communicate with all slave devices, allowing either controller to take over without requiring additional specialized equipment.
Solution Approach 2:
The second controller creates a copy of the control frames received from the first controller through loopback communication. This copying mechanism ensures that control information is preserved and can be transmitted continuously even when the first controller is stopped or fails, without requiring a complete duplicate system.
3Adaptability or versatility
If the controller performs firmware rewriting or maintenance, then the adaptability improves, but the productivity deteriorates because control is stopped
Solution Approach 1:
The second controller is pre-configured as a backup unit that can immediately assume control responsibilities. Before the first controller undergoes firmware rewriting or maintenance, the system is already in a state where the second controller can take over, eliminating downtime and maintaining productivity during updates.
Solution Approach 2:
The system maintains continuous control action through the backup controller during firmware rewriting or maintenance of the first controller. The second controller performs loopback communication and can transmit control frames without interruption, ensuring that slave devices continue operating and productivity is maintained while updates are performed.
Data Source
AI summary
This control system is provided with a plurality of slave devices and controllers. The controller is connected to one end of a field bus which includes the plurality of slave devices that is linearly connected, and the controller is connected to the other end of the field bus through a communication cable. The controllers are provided with a CPU and a transception part. One of the controllers generates a control frame with the CPU and transmits this from the transception part, and the other of the controllers performs a loop communication of the control frame by the transception part.