Field Device Clock Verification Using Network Reference Frequencies
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for checking clock generators in field devices require removal from their measuring points or involve additional circuitry, leading to inefficiencies in terms of space, energy, and frequency accuracy.
Innovation Solution
A method that utilizes multiple field devices with clock generators to verify the accuracy of a first clock generator by exchanging information, determining deviations, and comparing against a predefined tolerance range, allowing on-site checking without removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If external reference clocks are used to check clock generators, then frequency accuracy can be verified, but the field device must be removed from its measuring point which reduces productivity and increases loss of time
Solution Approach 1:
The field devices perform self-checking by exchanging timing information with each other through the existing process communication network. Each field device acts as both a service provider (checking its own clock) and service recipient (providing reference to others), eliminating the need for external reference clocks and device removal while maintaining frequency accuracy verification
Solution Approach 2:
The existing communication infrastructure between field devices is made multi-functional by adding clock verification capability. The same communication channels used for process data exchange are also used for timing information exchange, allowing clock checking without additional hardware or system modifications
2Reliability
If redundant reference clocks are installed within field devices, then clock accuracy can be maintained, but additional circuitry, space, and energy consumption are required
Solution Approach 1:
Other field devices in the network serve as intermediary reference sources for clock verification. Instead of each device carrying its own redundant reference clock, the networked field devices mutually verify each other's clocks by exchanging timing information, distributing the reference function across the system rather than duplicating it in each device
Solution Approach 2:
The clock verification function is merged with the existing process communication infrastructure. The timing information exchange is combined with the regular data communication between field devices, eliminating the need for separate reference clock hardware and integrating multiple functions into the existing system
Data Source
Figure 1
AI summary
The invention relates to a method for verifying at least one first clock generator (T1) of a first field device (F1) in a process measurement system (P), wherein the process measurement system (P) comprises the first field device (F1) and at least two further field devices (F2, F3), each with at least one clock generator (T2, T3), and wherein the method provides at least the following steps: - transmitting the generated actual frequency of the at least first clock generator (T1) to the at least two further field devices (F2, F3), - verifying the generated actual frequency of the at least first clock generator (T1) using the actual frequency of the respective clock generator (T2, T3) of the at least two further field devices (F2, F3), - determining reference frequencies of the at least first clock generator (T1) as a result of verifying the actual frequency of the at least first clock generator (T1).wherein the reference frequency is a frequency of the generated actual frequency of the at least first clock generator, determined based on the actual frequency of the respective clock generator of the at least two further field devices, - transmitting the reference frequencies to the first field device (F1), - determining the respective deviation of the reference frequencies from the target frequency of the at least first clock generator (T1) using the first field device (F1), - comparing the determined deviations and/or an average value of the determined deviations with a predefined tolerance range of the target frequency of the at least first clock generator (T1) using the processing unit, and - outputting at least one status message about the at least first clock generator (T1) based on the comparison using the processing unit.