tailieunhanh - Microprocessor Interfacing Techniques Lab VIEW Tutorial Part 8

Microprocessor Interfacing Techniques Lab VIEW Tutorial Part 8 | PHY 406 - Microprocessor Interfacing Techniques PHY 406 - Microprocessor Interfacing Techniques LabVIEW Tutorial - Part VIII Arrays and Clusters Arrays Clusters and Conglomerates LabVIEW has two group constructs arrays which are N-dimensional arrays of entities and clusters which in any other language would be called structures . Both of these are quite useful and are also essential for accessing some of the more powerful LabVIEW functions. We have already met arrays briefly in an example above. This VI makes up a 1-D array of random numbers 5 long. We examine this array by using the array shell from the array controls. Notice that at the moment this has no reality to it - it is just a shell because we don t know what sort of thing to display. To get further we drop a numeric indicator into the shell - now we know Array Output it will be a numeric array as opposed to an boolean array for example. The shell io noo now looks like this. The left-hand control is for the index - the right-hand value is the value of that index. Since we haven t actually wired the indicator up yet we don t know whether the index 0 is valid or not although it should be so the value is greyed out even though I changed the background colour to white. You can use the select tool to resize the indicator box to display more elements and when you have wired up the indicator to a real array and run the program the indicator comes to life. Notice that since the array size is 5 and array indices start from 0 the last element on the list doesn t exist and is therefore still greyed out. Now let s feed the array to a graph remember charts are for values which come one at a time graphs are for arrays . The result should be a simple graph of the value of the random number generator for five values each time you run the VI. A useful technique to learn at this stage is to highlight execution which allows you to run the VI in slow motion and watch the values being produced. This is controlled by the .