Field Device RF Circuitry Dynamic Power Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Field devices operating on process control loops with analog current between 4 and 20 mA face challenges in generating sufficient power for wireless communications without diminishing their ability to signal properly, as excessive power consumption can impair signal transmission.
Innovation Solution
A field device with RF circuitry that dynamically adjusts power consumption and is powered solely by the energy available from the process control loop, using a separate digital communication bus to manage power distribution and store excess energy for later use, allowing for efficient wireless communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wireless communication power is increased to ensure reliable RF communication, then communication reliability is improved, but power consumption increases and may impair the ability to signal properly over the current loop
Solution Approach 1:
The patent implements dynamic power adjustment of the RF circuitry based on real-time monitoring of available power from the process control loop. The system continuously adapts the transmission power level to match available energy resources, allowing reliable wireless communication when power is abundant while conserving energy when the loop current is low, thus resolving the contradiction between communication reliability and power consumption
Solution Approach 2:
The system changes the power consumption parameter of the RF circuitry based on the operating conditions of the process control loop. By monitoring the loop current and available power, the system adjusts the RF transmission power parameter dynamically, enabling reliable communication when power is available while maintaining proper signaling capability when power is constrained
2Use of energy by moving object
If a separate power source is added to support wireless communication, then power availability for RF circuitry is improved, but device complexity and installation requirements worsen
Solution Approach 1:
The patent enables the field device to serve its own power needs by extracting and managing power from the existing process control loop. The system monitors the loop current and intelligently allocates power between the process signaling function and wireless communication, eliminating the need for external power sources or batteries while maintaining both communication and signaling capabilities
Solution Approach 2:
The process control loop is made multi-functional by enabling it to simultaneously provide both process control signaling and power for wireless communication. The system design allows the same two-wire connection to serve dual purposes: carrying process data and providing electrical power, thereby eliminating the need for separate power infrastructure and reducing installation complexity
Data Source
AI summary
A field device for use in an industrial process control or monitoring system includes terminals configured to connect to a two-wire process control loop configured to carry data and to provide power. In one embodiment, RF circuitry in the field device is configured for radio frequency communication having variable power consumption. In another embodiment, the RF circuitry is coupled to the field device through a separate digital communication bus. A method of modulating the power of RF communication based upon a process communication signal is also provided.