Components of a Computer System ADCs Data Loggers

Components of a Computer System ADCs - Data Loggers 12/30/2021 1

Learning Objectives State the difference between analogue data and digital data. Describe the need for conversion between analogue and digital data. Name the general name for devices which do this conversion. Explain that a “data logger” converts analogue signals to digital so that computers can understand the data readings from sensors. 12/30/2021 2

Structure Diagram COMMUNICATIONS MAIN MEMORY INPUT DEVICES PROCESSOR ROM OUTPUT DEVICES AUXILIARY STORAGE 12/30/2021 3

Communications Sending and receiving data to and from other computers or devices. 12/30/2021 4

Analogue Data Analogue devices such as: n n Clocks Thermometers Phones Speakers Represent variables by an analogous quantity or variations (modulations) : n n n Time is represented by the angle of the hands Temperature is represented by the height of a column Sound waves on a normal phone line or from speakers. 12/30/2021 5

Digital Data Computers work with data in a digital form. n Streams of 0's and 1's 12/30/2021 6

Need for conversion If computers are to receive or send analogue data (sensors, speakers, phone lines, etc…). n n There must be conversion between analogue and the digital data computers use. Devices which do this are called: ADCs (Analogue to Digital Converters) 12/30/2021 7

Data Loggers n Convert analogue data from sensors to digital data which a computer can understand. 12/30/2021 8

Sound Cards Sound cards n n Convert digital data to analogue data for speakers / headphones to use. Convert analogue data from microphones to digital data which a computer can understand. 12/30/2021 9

Plenary What is the difference between analogue data and digital data? n Analogue data: analogous quantity or variations (modulations) n n Time is represented by the angle of the hands Temperature is represented by the height of a mercury column Sound waves on a normal phone line and or from speakers. Digital data: Streams of 0's and 1's 12/30/2021 10

Plenary Why do we need to convert between analogue and digital data? n Computers work with data in a digital form. What are devices that do this conversion called, can you name three examples and state when they are used? n ADCs (Analogue to Digital Converters) Data Loggers - Convert analogue data from sensors to digital data. Sound Cards - Converts digital signals to analogue data and for speakers to use and vice versa from microphones. 12/30/2021 11

Plenary In which types of network is a modem necessary and unnecessary? n Modem needed: WANs n Modems not needed: LANs 12/30/2021 12