Components of a Computer System ADCs - Data Loggers 22/05/2019

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. 22/05/2019

Structure Diagram INPUT DEVICES MAIN MEMORY PROCESSOR OUTPUT DEVICES AUXILIARY STORAGE ROM COMMUNICATIONS 22/05/2019

Communications Sending and receiving data to and from other computers or devices. 22/05/2019

Analogue Data Analogue devices such as: Clocks Thermometers Phones Speakers Represent variables by an analogous quantity or variations (modulations) : 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. 22/05/2019

Digital Data Computers work with data in a digital form. Streams of 0's and 1's 22/05/2019

Need for conversion ADCs (Analogue to Digital Converters) If computers are to receive or send analogue data (sensors, speakers, phone lines, etc…). There must be conversion between analogue and the digital data computers use. Devices which do this are called: ADCs (Analogue to Digital Converters) 22/05/2019

Data Loggers Data Loggers Convert analogue data from sensors to digital data which a computer can understand. 22/05/2019

Sound Cards Sound cards Convert digital data to analogue data for speakers / headphones to use. Convert analogue data from microphones to digital data which a computer can understand. 22/05/2019

Plenary What is the difference between analogue data and digital data? analogous quantity or variations (modulations) 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 22/05/2019

Plenary Why do we need to convert between analogue and digital data? 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? 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. 22/05/2019

Plenary In which types of network is a modem necessary and unnecessary? Modem needed: WANs Modems not needed: LANs 22/05/2019