RS-422 Serial Bus Timing for Multi-Driver Datagram Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing RS-422 connections cannot connect multiple drivers to a single bus while maintaining the ability to distinguish between datagrams received by the listener, posing challenges in legacy systems that rely on RS-422 for stability and compatibility.
Innovation Solution
Implementing a serial connection with a common external trigger signal, individual delays, and high impedance output control to enable multiple RS-422 drivers to transmit sequentially on a shared bus, ensuring each driver has a unique identification number and predetermined delay to avoid overlap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple RS-422 drivers are connected to the same bus, then the quantity of connected devices is improved, but the ability to distinguish between datagrams deteriorates
Solution Approach 1:
The patent applies preliminary action by implementing a trigger mechanism that activates drivers in a predetermined sequence before data transmission occurs. Each driver is assigned a unique trigger activation time, ensuring that only one driver transmits at a time while all drivers remain connected to the same bus. This preliminary timing arrangement prevents data collision and maintains distinguishability without requiring separate buses for each driver.
2Productivity
If multiple drivers transmit continuously on the same bus, then the productivity of data transmission is improved, but the reliability of data distinction deteriorates
Solution Approach 1:
The patent implements periodic action through a trigger-based transmission system where drivers transmit data in periodic cycles rather than continuously. The trigger mechanism creates discrete transmission windows for each driver in a predetermined sequence, allowing continuous operation across multiple drivers while maintaining clear temporal separation between their transmissions. This periodic structure ensures both high productivity and reliable data distinction.
3Adaptability or versatility
If RS-485 connection is used instead of RS-422, then the adaptability to multipoint connections is improved, but the compatibility with legacy systems deteriorates
Solution Approach 1:
The patent applies universality by designing a system that maintains RS-422 interface compatibility while achieving multipoint capabilities. The trigger mechanism and sequential transmission protocol enable multiple drivers to share a single RS-422 bus without requiring physical changes to the interface hardware. This approach preserves full RS-422 compatibility for legacy systems while providing the adaptability of multipoint connections through software-based time-division multiplexing.
Data Source
AI summary
Serial connection for connecting a listener to at least two drivers through a single serial bus and a common connection carrying an external trigger signal, wherein each driver comprises:a first receiver transmitter of the FIFO type, configured as a transmitter, connected in between the serial bus and a data transmitter connected to data generation means,an external trigger input connected to the common connection, to a timer and a data latch,a high impedance output control connected to the first receiver transmitter, configured to not allow data through unless a command is received from a toggle signal transmitter,a timer connected between the toggle signal transmitter and the high impedance output control, configured to allow the command from the toggle signal transmitter to go through after lapsing of a predetermined duration starting as an external trigger event happens, the external trigger event being based on the external trigger signal, the predetermined duration being different for each driver, anda data latch connected between the data transmitter and the first receiver transmitter, configured to allow the data through, upon detecting the external trigger event.