4~20mA to rs232, need to design a conversion board, the main functional devices on the board, including integrated ADC MCU and 232 interface chip. The conversion process is as follows:
The first step is to convert 4~20mA into a digital quantity using the ADC inside the MCU.
The second step is to convert the rs232 interface chip to the corresponding serial communication with the single chip computer serial port.
If the accuracy of analog-to-digital conversion is high, ADC conversion also needs a reference power supply chip.