Aperture Type Functions

One way of using aperture types is to enter a automatic control function. Functions are a way of controlling the aperture opening proportion based on zone temperature, outside temperature, and wind speed. Seven basic modes of operation have been implemented and are described in the following sections:

Each mode has been given an acronym, with each letter representing part of the control process. However, it is best to think of these acronyms simply as a label for the mode. To use, click on the word 'Opening' in the gains table and select 'Function' from the 'Type' drop down list. Then select the mode by left clicking on its name, left click on the 'Next' button. Enter the values for the parameters and left click on the 'Finish' button.

 

It is possible to use both Factor and Aperture Schedule to modify the behaviour of the automatic control. The Factor value in the Aperture Types profile is always multiplied with the aperture opening value from the automatic control function. The factor value should be set as the maximum opening proportion of the aperture.

 

When scheduling is used in conjunction with automatic control, very complex systems can be created and simulated. The value from the Aperture Schedule (either zero or one) is multiplied with the opening value from the automatic control function. This allows an aperture to be automatically controlled, and available, at only certain times of day.

 

Each mode can be thought of as a number of 'rules' e.g. closing the window above a certain wind speed is a rule in all the modes. Each rule can then be thought of as a function, producing a 'signal', a value from zero to one, that indicates whether the window should be open ('1') or shut ('0'). For example, the wind rule can be represented by this graph.

 

image\help0030_wmf.gif

 

A typical zone temperature rule by this graph.

 

image\help0031_wmf.gif

 

Any of the cut-off rules as this graph.

 

image\help0032_wmf.gif

The rule that the aperture should close when the outside temperature is higher than the inside is a similar graph to the last one, but with outside temperature replacing the cut-off value.

 

During simulation the selected mode will calculate the appropriate signal value from each of its rules. The final aperture opening value is simply the product of all of the signals. In this way a rule that specifies 'shut', with a signal value of zero, will force the aperture closed no matter what the other rules are returning. Likewise, a rule that specifies that the aperture should be open, a signal value of one, will have no effect on the other rules. It is only when all signals are one that the aperture will be completely open.

 

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