Data logging & control systems

Data logging & control systems

1. data logging

   • Advantages
     • take readings with high degrees of accuracy
     • No one will forget a reading
     • be left without human intervention
     • take many readings in a short period of time
     • Line, pie or bar graphs can be generated
     • no likelihood of human error
   • Disadvantages
     • Equipment can be expensive for small tasks
     • If the data logging equipment breaks down or malfunctions, some data could be lost or not recorded
     • The equipment will only take readings at the logging interval which has been set up
     • Sensors must be carefully calibrated otherwise they could be taking the wrong readings
   • Sensors
     • The logging period is the total length of time over which readings are taken.
     • Sensors have an important role in the data logging process. sensors such as light, heat, sound, pressure, acidity and humidity.
     • The time interval for data logging is the time between readings.
   • remote data logging
     • record data 'out in the field'

2. Control systems

   • Advantages
     • Can operate 24hours a day without a break
     • can process data from sensors quickly
     • Computers can repeat actions in an identical way indefinitely
     • Computers can work in environments that are dangerous for people
   • Disadvantages
     • The software for the control system is specialist and may cost a lot of money to develop
     • If there is a power cut the system will not work
     • A computer is only as good as its programming, which may contain errors
     • A computer is only as good as its programming, which may contain errors
   • control systems are used to;
     • operate systems, eg traffic lights
     • control actions, eg a robot’s movement
     • create video games
     • control manufacturing devices, eg laser cutters
   • control systems within home;
     • electric kettles
     • washing machines
     • tv remotes
     • tv recording devices
     • security lights