computer data logging and control lesson objective: understand the main terminology based about...
TRANSCRIPT
Computer Data Logging and Control
Lesson Objective:Understand the main terminology based about Data Logging and Models
Learning Outcome:Complete the questions on the worksheet.
Keywords: Data logging, logging period, logging interval, thermistor, thermostat, dedicated system, computer control, feedback loop, DAC ADC
What is happening in this picture?
Measuring temperature change.
Time Temperature
00:30 0.5 ˚C
01:00 0.5 ˚C
01:30 0.75 ˚C
02:00 1.0˚C
02:30 1.0˚C
Recordings would appear like this:
…etc.
How often and how long?
The time interval between measurements is called the logging interval.
The total time taken to take all of the recordings is called the logging period.
What is the logging interval and logging period of this experiment?
Time Temperature
00:30 0.5 ˚C
01:00 0.5 ˚C
01:30 0.75 ˚C
02:00 1.0˚C
…etc.
59:00 21.75˚C
59:30 22.0˚C
60:00 22.0˚C
Logging interval = 30 seconds, Logging period = 60 minutes.
How to determine the logging interval and logging period …
The logging interval depends on how often the data is likely to change. (e.g. the temperature of ice melting into water- every 30 seconds is accurate enough)
The logging period depends on how long it takes for the data to stop changing (60 minutes for ice melting?)
A temperature sensor-Thermistor
Thermistors can be connected to computers and can be used to take temperature recordings over time. You must tell the software the logging interval and the logging period.
Weather stations use data logging equipment.
What do you think is being measured by this remote weather station?
What would the logging interval and logging period be for this?
Why do data logging? Can do it in Inhospitable
places
Records Accurately
Can Record over very long or short intervals
Don’t need Breaks (like humans!)
Easy Acronym:
I
Am
Recording
Boyzone
Control systems
Dedicated Computer Controlled
Feedback Loops The results of the output become part
of the input which can affect the process.
Digital and Analogue
Digital data is stored as 0’s and 1’s
Digital information occurs in steps
Analogue information makes gradual changes
Analogue data can be stored as writing, sound, …etc.
Digital to Analogue Converter
Digital and Analogue signals
Computer
No entry to Analogue
Analogue Signals
Analogue SignalsAnalogue
to Digital Converter
DIGITAL ONLY!
Models and simulations
A model is the re-creation of a process or an object.
A simulation is carried out using a model.
The model must be built or programmed first.
The model is then used to test “real life” situations.