Abstract
With the production process to the continuous, large, complex development, the requirements of control need to be higher, plus all kinds of new control scheme and the application of advanced control law to the practice continuously, the traditional instruments come to be competent, their limitations become very prominent. With the fieldbus control system,s development, fieldbus intelligent instrument came into being, and have achieved rapid development. The theory of intelligent PID control that has been widely used was applied, as the system,s main part of the control. In the Circuit Design, +5 V and +15 V voltage circuit and watchdog circuit were used; in the input part of the signal, a differential amplifier circuit and A/D574 were applied, so it can be smaller error signal and has high resolution;in the output part used the TLC5616 and output amplifier. As the number of the keyboard is smaller, used a simple structure for the independent keyboard. But the digital display are more, in order to save IO mouth lines, a dynamic show circuit was used. In order to implement the real-time monitoring of the signal changes, and in order to achieve communications of the single chip and the PC, used the environment adaptative and more cost-effective of the RS485 bus.
Keywords Fieldbus intelligent instrument Proportion Integral Differential control independent keyboard single chip dynamic display
目 录