Programmable Discrete Input Module for Isolated Multi-Voltage Signals

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Solution Overview

Problem

Industrial control systems require multiple dedicated input/output modules to interface with instruments operating at different voltage levels, leading to increased complexity and cost, as well as a need for galvanic isolation to prevent electrical interference.

Innovation Solution

A programmable discrete input/output module that includes a pulse width modulation module, isolator, comparators, and a microcontroller, allowing for generation of isolated signals and comparison with programmable reference values, and providing galvanic isolation to operate across various voltage levels (24V, 48V, 120V, 240V) without requiring multiple modules.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple dedicated input/output modules are used to interface with instruments operating at different voltage levels, then the system can handle various voltage levels (24V, 48V, 120V, 240V), but the device complexity and cost increase

Engineering Contradiction:
Improvevoltage level compatibilityVSAvoidnumber of modules
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a single universal input module that can interface with instruments operating at multiple voltage levels (24V, 48V, 120V, 240V AC/DC) through programmable configuration. The module uses a pulse width modulation (PWM) interface with isolator that can be programmed to accept different voltage inputs and convert them to a standardized internal signal, eliminating the need for multiple dedicated modules for different voltage levels.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The module employs programmable parameters including voltage level selection, PWM frequency adjustment, and isolator configuration to adapt to different voltage inputs. By changing these parameters through software configuration rather than hardware redesign, the single module can handle various voltage levels effectively.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If galvanic isolation is implemented to prevent electrical interference, then the reliability improves, but the device complexity increases

Engineering Contradiction:
Improveelectrical isolationVSAvoidisolation circuitry
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces an isolator as an intermediary component in the signal path between the PWM interface and the internal circuitry. This isolator provides galvanic isolation to prevent electrical interference and ground loops while maintaining signal integrity. The isolator acts as a mediator that transfers signal information without direct electrical connection, thereby improving reliability without requiring complex isolation circuits throughout the entire system.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If dedicated modules are used for each voltage level, then the measurement precision and control accuracy are maintained, but the cost increases

Engineering Contradiction:
Improvesignal accuracyVSAvoidmodule quantity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The single universal module maintains measurement precision through programmable PWM frequency selection and isolator configuration that can be optimized for each voltage level. The module includes programmable parameters that allow precise signal conditioning and conversion regardless of the input voltage level, ensuring accurate measurements and control signals are maintained across all supported voltage levels.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The module reduces the number of required modules by providing AC/DC functionality, simplifying operations and reducing costs by allowing users to select programmable references and hysteresis, while ensuring reliable communication and control across different voltage environments.

Implementation Method 1

a pulse width modulation module configured to generate a pulse width modulated signal based upon an input signal

Methodology Applied
Scientific EffectPulse width modulation: Phase Modulation

Implementation Method 2

an isolator communicatively coupled to the pulse width modulation module, the isolator being configured to isolate the pulse width modulation module and a pulse width demodulation module

Methodology Applied
Scientific EffectGalvanic isolation: Electrical Impedance Tomography

Data Source

PatentEP3486738B1Programmable discrete input module and respective method
Publication Date: 2022.03.23 BEDROCK AUTOMATION PLATFORMS INC
  • EP3486738B1 patent drawingFigure 1
  • EP3486738B1 patent drawingFigure 2
  • EP3486738B1 patent drawingFigure 3A~3B

AI summary

A programmable discrete input module (400) is described. The programmable discrete input module comprises a pulse width modulation module (404) configured to generate a pulse width modulated signal based upon an input signal and a pulse width demodulation module (434) configured to generate a demodulated pulse width signal. An isolator (424) is configured to isolate the pulse width modulation module and the pulse width demodulation module and to generate isolated modulated pulse width signal based upon the pulse width modulated signal for the pulse width demodulation module to generate the demodulated pulse width signal. The programmable discrete input module also includes a comparator (440) for comparing the demodulated pulse width signal with a respective programmable reference to generate a discrete input signal.