基于MSP430的二线制高精度表头设计

Design of Two-wired High Precision Meter Based on MSP430

针对传统的二线制表头在高温下测量精度差、温漂大的特点,提出了一种在高温下的高精度数显表头的设计方案。分别介绍了其软硬件的实现方法,即采用超低功耗微处理器MSP430F4250采集回路中的电流值,采用24位ADC转换器ADS1244进行模数转换,最后将经过运算的变送器输出信号值在LED数码管中加以显示。实测结果证明,该表头在高温下测量精度高、工作可靠、抗干扰性强、实用性强,势必会成为无源二线制仪表的发展方向。

Poor accuracy and big drift are the disadvantages of traditional two-wired indicators in measurement under high temperature, thus a design strategy for high precise digital indicator has been proposed. The implementing methods of hardware and software are introduced respectively. In the design, the super-low power consumption microprocessor MSP430FF4250 is used for collecting the circuit values in the loop; the 24-bit AD converter ADS1244 is used for AD conversion; and the calculated transmitter outputs are displayed on LED. The practical test result shows that the indicator features high accuracy, reliable operation, good anti-interference capability and strong practicality under high temperature. It will be the future developing trend for two-wired passive instruments.