The analog input module is an intelligent module that can collect analog values such as voltage, current, thermocouple, thermal resistance, temperature, etc., and transmit them to the computer through the 485 bus. The main function of the analog output module is actually to convert the input digital signal into a digital analog, and output adjustable continuous voltage, current, and signal. For example, in the control of various analog quantities in the TV control block, taking accompanying sound as an example, the pulse digital signal emitted by the remote control or button scanning is first input into the control block, and after the analog-to-analog conversion of the analog output module, a continuous voltage signal that can change with the input signal is output. Then, this signal is used to control the accompanying sound channel, thereby controlling the volume, brightness, and contrast