上海充通大学 SHANGHAI JIAO TONG UNIVERSITY 2.3 Analog Digital Modes of Operation The measured variable's information can be represented by Digital Signal or Analog Signal. 0.5 0 -Analog Signal 200 4p0 600 一Digital Signal -0.5 Examples: Digital Device:Fig.2.4 上海充通大学 SHANGHAI JIAO TONG UNIVERSITY 2.3 Analog Digital Modes of Operation For analog signal,the precise value of the quantity (voltage, rotation angle,etc.)carrying the information is significant. Digitized signal lost some information,it is an important issue to choose the number of bits in digitizing unit of an instrument so the useful information can be preserved properly. Digital Signal is easier for transmission,storage.... Two important components for a digital instrument: ADC Analog to Digital Converter DAC Digital to Analog Converter2.3 Analog & Digital Modes of Operation The measured variable’s information can be represented by Digital Signal or Analog Signal. -1 -0.5 0 0.5 1 0 200 400 600 Analog Signal Digital Signal Examples: Digital Device: Fig. 2.4 2.3 Analog & Digital Modes of Operation For analog signal, the precise value of the quantity (voltage, rotation angle, etc.) carrying the information is significant. Digitized signal lost some information, it is an important issue to choose the number of bits in digitizing unit of an instrument so the useful information can be preserved properly. Digital Signal is easier for transmission, storage…. Two important components for a digital instrument: ADC = Analog to Digital Converter DAC = Digital to Analog Converter