1 Characteristics of today’s instruments and meters
1.1 Softwareization of hardware functions
With the development of microelectronics technology, microprocessors are getting faster and faster, and their prices are getting lower and lower. They have been widely used in instruments and meters, making some functions that have high real-time requirements and were originally completed by hardware now available through software. Even many problems that were difficult to solve or could not be solved at all with hardware circuits can be well solved with software technology. The development of digital signal processing technology and the widespread adoption of high-speed digital signal processors have greatly enhanced the signal processing capabilities of instruments. Digital filtering, FFT, correlation, convolution, etc. are common methods of signal processing. Their common feature is that the main operations of the algorithm are composed of iterative multiplication and addition. If these operations are completed by software on a general-purpose microcomputer, the operation time is long. The digital signal processor completes the above multiplication and addition operations through hardware, which greatly improves the performance of the instrument and promotes the widespread application of digital signal processing technology in the field of instruments and meters.
1.2 Integration and modularization
With the development of large-scale integrated circuit (LSI) technology to today, the density of integrated circuits is getting higher and higher, the size is getting smaller and smaller, the internal structure is getting more and more complex, and the functions are getting more and more powerful, which greatly improves the integration of each module and the entire instrument system. Modular functional hardware is a strong support for modern instrumentation. It makes the instrument more flexible and the hardware composition of the instrument more concise. For example, when a certain test function needs to be added, only a small amount of modular functional hardware needs to be added, and then the corresponding software can be called to use this hardware.
1.3 Real-time parameter setting and modification
With the development of various field programmable devices and online programming technologies, the parameters and even the structure of instrumentation do not need to be determined at the time of design, but can be placed and dynamically modified in real time at the site where the instrument is used.
1.4 Universal hardware platform
Modern instrumentation emphasizes the role of software, selects one or several basic instrument hardware with commonality to form a universal hardware platform, and expands or forms instruments or systems with various functions by calling different software. An instrument can be roughly decomposed into three parts: 1) data acquisition; 2) data analysis and processing; 3) storage, display or output. Traditional instruments are assembled by manufacturers in a fixed way according to the functions of the instrument. Generally, an instrument has only one or several functions. Modern instruments combine general hardware modules with one or more of the above functions, and form any instrument by compiling different software.