在过程控制及各种仪器仪表中,当由微型计算机进行实时控制及实时数据处理时,计算机所能加工的信息总是数字量,而受控制或被测量对象的有关参量往往是一些连续变化的模拟量,如温度、压力、流量、速度等。因而必须将这些模拟量转换为数字量才能由计算机进行加工处理,这一转换称量化过程。由计算机加工处理了的数字量也往往需要转换为模拟量,以便对受控对象进行控制。前者称为模数(A In process control and various instruments, when the real-time control and real-time data processing by the microcomputer, the computer can process the information is always digital, and the controlled or measured object of the relevant parameters are often some continuous changes Analog, such as temperature, pressure, flow, speed and so on. Therefore, these analog quantities must be converted into digital quantities to be processed by the computer. This conversion is called the quantification process. The digital quantities processed by the computer also often need to be converted to analog quantities in order to control the controlled objects. The former is called modulus (A