CXPI Bus Scheduling for Sequential Load Control
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Solution Overview
Problem
Existing network communication systems struggle to transmit command signals for sequentially operating multiple loads with short time differences over networks with relatively low communication speeds, limiting the flexibility and precision of light emission patterns in vehicle lighting systems.
Innovation Solution
A network node with a discriminator, specified number acquisition unit, delay information detection unit, and determination unit that calculates and applies delay times to output signals based on received command signals, allowing for precise timing of operations signals across multiple output ports, regardless of network speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If command signals are transmitted via a network with relatively low communication speed, then the network can be used for non-critical loads, but the transmission interval between successive command signals must not be less than an upper limit, restricting the light emission pattern
Solution Approach 1:
The master controller transmits delay information along with the command signal, allowing slave controllers to pre-calculate their output timing. This preliminary provision of timing data enables short time differences between sequential load operations even over low-speed networks, as the delay calculation is performed in advance rather than requiring real-time communication during the sequencing operation.
2Productivity
If ten LED devices emit white light at short intervals, then the lighting effect is achieved, but ten types of control signals must be transmitted over the network, increasing communication load
Solution Approach 1:
Multiple control signals for sequential LED operations are merged into a single command signal that includes delay information. Instead of transmitting separate control signals for each LED device timing, the system combines all timing information into one signal that slave controllers use to determine their respective output times, significantly reducing the number of transmissions required.
Solution Approach 2:
The command signal structure is designed to be universal, serving multiple functions simultaneously: it identifies the target output port, specifies the delay period, and triggers the operation. This multi-functional signal design eliminates the need for separate dedicated signals for each control parameter, reducing overall communication load while maintaining full control capability.
Data Source
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AI summary
In a network communication system, the controller of a master unit sends a control signal to a CXPI bus. The controller specifies load turn-on intervals as delay times in a delay range of the command signal and specified ports of slave units in an output port specification range, in a specific order corresponding to the turn-on sequence of the loads. The microcomputer of each slave unit receives the control signal from the CXPI bus. The microcomputer detects a specific number of times a port of its own slave unit, specified as the command destination in the output port specification range, integrates the specified values in the delay range, and outputs the operating signal to the specified port at a time delayed from the receipt of the command signal by the time interval calculated by the integration.The number of specified values is a number obtained by subtracting 1 from the specified number.