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1 Introduction to LabVIEW Programming OBJECTIVE Doing experiment of control system is essential to knowing the comparison between control theory and practical. The practice is on physical system modeled and made an interface using LabVIEW. The physical model is used to make a virtual plant in formed an GUI, so the operator could operate the system easily. REFERENCE LabVIEW s Training Presentation: Introduction to LabVIEW. LabVIEW s Manual Instruction EXPERIMENT EQUIPMENT In this experiment will used some servos as shown Table 1. Table 1 Equipment of DC Motor Position Control Experiment Quantity Designation Description 1 PC Personal Computer 1 LabVIEW 2015 Software Programming LESSON 1 : INTRODUCTION LabVIEW (Laboratory Virtual Instrument Engineering Workbench) is a graphical programming language that uses icons instead of lines of text to create applications. In contrast to text-based programming languages that use instructions to determine the order of program execution, LabVIEW uses dataflow programming. In data flow programming, the flow of data through the nodes on the block diagram determines the execution order of the VIs and functions. VIs, or virtual instruments, are LabVIEW programs that imitate physical instruments. In LabVIEW, you build a user interface by using a set of tools and objects. The user interface is known as the front panel. After you build the front panel, you add code using graphical representations of functions to control the front panel objects. You add this graphical code, also known as G code or block diagram code, to the block diagram. The block diagram somewhat resembles a flowchart. The block diagram, front panel, and graphical representations of code compose a VI. The following illustration shows a front panel and its corresponding block diagram. Starting Program 1. Click File New Blank VI 1

2 Figure 1.1 First interface to start program The fitur of LabVIEW and Virtual Instrument LabVIEW programming software has several main components there are block diagram, front panel, connector pane, and highlihgt execution. Block diagram s window is used to create a logical, arithmatic, or another programming activity. This window show program block which will be used when create a program. Front panel s window is used to make an interface design. In this window there are many tool which is used to create an animation from the desain, data presenting and data accusition. Highliht execution is tools which used to show the step of execution of program. Figure 1.2 show the form of block diagram and front panel window, and also the highlight execution tools. BLOCK DIAGRAM HIGLIGHT EXECUTIO N FRONT PANEL CONNECTOR PANE Figure 1.2 Interface of main compinent in LabVIEW Front panel, block diagram, and connector paneis called virtual ictor instrument. Front panel as an user interface to control and make some indicators. Block diagram as a graphical source 2

3 code, create data travels on wire from control terminal through function to indicator terminal. Connector pane as a graphical representation of a VI. Project Explorer This tool is used to 1. Regroup LabVIEW files(.vi) and non LabVIEW files. 2. Build specification such as standalone application 3. Deploy or download files to the target like FPGA target. Front Panel Toolbar Figure 1.3 Example of Project Explorer Figure 1.4 Front panel toolbar Do not click abort button to stop the loop, because there is no guarantee that PC clean up memory correctly. 3

4 Panel Control and Indicator control indicator Block Diagram Toolbar Figure 1.5 Control and indicator on LabVIEW Figure 1.6 Block diagram's toolbar Terminals 1. Block diagram is a representation from front panel. 2. As a gate between block diagram and front panel. Wires 1. Data send beetwen block diagram. 2. Have differents color based on data type. 3. A broken wire show dashes line. Figure 1.7 Data type relation to wire's type 4

5 Wiring Tips: 1. Click <Ctrl> - B to clean up the broken wire. 2. Right click dan choose clean up wire to trace the wire automaticaly. BEFORE AFTER Figure 1.8 After and before clean up wire Block Program Functions 1. The basic elements of operations in LabVIEW 2. Have not a front panel, or block diagram but has connectors 3. Double-click on a function will only select a function, not open like VI 4. Have a yellow Data background Type Figure 1.9 Block Program subvis 1. VI yang dibuat untuk membentuk VI lain 2. Semua VI berpotensial menjadi subvi 3. Klik dua kali pada subvi akan membuka isi dai subvi 4. Ikon merepresentasikan subvi di VI utama Structures 1. While loops, for loops, dan event structures Figure 1.10 Data type 5

6 Control and Function Numerical Data Figure 1.11 Numerical Data Pallet (Front Panel) Right click control tab modern numerical subpalette chose numeric control icon. (Block Diagram) Right click control tab programing numerical subpalette chose numeric control icon. Mathematical Operation (Block Diagram) Right-click the Functions»Mathematics» Integration and Differentiation sub palette, select Derivative x (t).vi Figure 1.12 Math Palete 6

7 Bolean Control and Function String Data Funtion and Control Figure 1.13 Boolean control and indicator Figure 1.14 String pallet (Front Panel) Right Click Controls»Modern» String sub palette, select the String Control icon. (Block diagram) Right Click Function»Programming» String sub palette, select the Concatenate icon. Data Flow 1. Execution of the block diagram depends on the flow of the data 2. Block diagrams executed from left to right. 3. Node will execute when there is value in all terminals. 4. Nodes distribute data to all output terminals when done. 5. If the computer running the program has more than one processor, then the two programs can be run separately without any additional coding 7

8 Figure 1.15 Data flow block diagram Array Array data consists form dimention and element. It means the element fill the array data, and the dimention define the size of data. Figure 1.16 Array dimension and number Index Array Show the dimention 1D until n-d. Element show in the corner left up side. Figure and 2 dimension array 8

9 Element of Array Array can be formed into various types of data, but an array can only be formed by one types of data. Figure 1.18 Type of Array Intialized and unitialized Array If the elements in a gray-colored array, then the element uninitialized. Uninitialized element has no value. Figure 1.19 Initialized and uninitialized array Array function: 1. Array size : show the total element every dimention in some array data. 2. Index array: Show value in some index. 3. Initialize array: Make an array data based on predefined dimention. 4. Build array: Add an element or dimention on array. 5. Search 1D Array: Show the data founded index. Clusters Clusters is a group of data element form different data type. There are several function: 1. Bundle or unbundle is used for create a cluster or seperate the cluster data. 9

10 2. Bundle by name or Unbundle by name, changing one or more elements of the cluster. This function switch element cluster based on the given name of the sequence position on cluster. Figure 1.20 Cluster pallet 3. Cluster constant give a constan value in form of cluster. Sequence Cluster 1. Elements of the cluster has a logic sequence. The sequence logic is not determined from the position of elements on the cluster. 2. Set the order can be done in a way; right-click on the cluster border and select Reorder Controls in Cluster on the shortcut menu 3. The sequence determines how the cluster will be unbundled. Figure 1.21 Sequence Cluster Clusters and Array 1. Clusters differ from the array, in example cluster discount fixed size. 2. Clusters can consist of many types of data; the array is only one type of data. 3. Such as arrays, clusters can be referred to as a control or indicator, cannot be called both. 4. Clusters can be made from the cluster, the cluster of arrays, arrays of clusters, but not the array of arrays. 10

11 EXPERIMENT 1: Creating a New VI Figure 1.22 Clusters and array 1. Clik start All Programs National Instrument LabVIEW 2. Click File New Blank VI 3. Create your first program called calculator like in Figure 1.11 EXPERIMENT 2: Creating an Arrays 1. Controls»Modern»Array, Matrix, and Cluster subpalette, pilih ikon Array. 2. Drag the data or element to shell array Figure 1.23 Create an array Figure 1.24 Interface of array data in front panel 11

12 3. Create an array absent data, like the picture below: Figure 1.25 Absent program LESSON 2 : LOOP AND CASE Loop and Case are including Structures function in LabVIEW. Structures contain sections of graphical code and control law how and when the code inside is run. The most common execution structures are While Loops, For Loops and Case structures which you can use to run the same section of code multiple times or to execute a different section of code based on some condition. Figure 2.1. Structure Function in LabVIEW In Figure 2.1., we know there are many item in Structure Function, 12

13 For Loop : Executes a sub diagram a set number of times. While Loop : Executes a sub diagram until a condition is met. Case structure : Contains multiple sub diagrams, only one of which executes depending on the input value passed to the structure. Flat Sequence structure : Contains one or more sub diagrams, which execute in sequential order. Formula Node : Performs mathematical operations based on numeric input. In this experiment we will use three items from the Structure Function, which are While Loop, For Loop and Case Structure. WHILE LOOP A While Loop is a structure that repeats its body until a test condition fails. similar to a Do Loop or a Repeat-Until Loop in text-based programming languages, the While Loop, shown in Figure 2.2, executes the code it contains until a condition occurs. Figure 2.2. shows a While Loop in LabVIEW, a flowchart equivalent of the While Loop functionality, and a pseudo code example of the functionality of the While Loop. The While Loop is located on the Structures palette. Select the While Loop from the palette and then use the cursor to drag a selection rectangle around the section of the block diagram you want to repeat. When you release the mouse button, a While Loop boundary encloses the section you selected. Add block diagram objects to the While Loop by dragging and dropping them inside the While Loop. Figure 2.3. Stop if True Figure 2.4. Continue if True 13

14 The While Loop executes the code it contains until the conditional terminal, an input terminal, receives a specific Boolean value. You also can perform basic error handling using the conditional terminal of a While Loop. When you wire an error cluster to the conditional terminal, only the True or False value of the status parameter of the error cluster passes to the terminal. Also, the Stop if True and Continue if True shortcut menu items change to Stop if Error and Continue while Error. Figure 2.5. Iteration terminal The iteration terminal (see Figure 2.5) is an output terminal that contains the number of completed iterations. The iteration count for the While Loop always starts at zero. FOR LOOP A For Loop iterates the number of times specified; however, if the total number of iterations is zero or negative, it will not run. Note that the For Loop is available in the diagram window and not in the Front Panel. This is because the For Loop is related to a functionality of instruments and not to data display or input switches. The For Loop executes a sub diagram a set number of times. Figure 2.6 shows a For Loop in LabVIEW, a flowchart equivalent of the For Loop functionality, and a pseudo code example of the functionality of the For Loop. Figure 2.6. For Loop The For Loop is on the Structures palette. You also can place a While Loop on the block diagram, right-click the border of the While Loop, and select Replace with For Loop from the shortcut menu to change a While Loop to a For Loop. Figure 2.7. Loop count The count terminal is an input terminal in Loop count (see Figure 2.7) whose value indicates how many times to repeat the sub diagram. 14

15 Figure 2.8. Loop iteration The iteration terminal is an output terminal in Loop iteration (see Figure 2.8) that contains the number of completed iterations. The iteration counts for the For Loop always starts at zero. The For Loop differs from the While Loop in that the For Loop executes a set number of times. A While Loop stops executing only if the value at the conditional terminal exists. CASE STRUCTURE A Case structure in LabVIEW is analogous to the If And Else Statement in text-based programming languages. However, realization of Nested If And Else Statements in LabVIEW requires more attention since LabVIEW provides graphical conditional selection in a two-dimensional diagram window. The Nested If And Else Statements can be realized by Nested Case Structure or Multiple Frame Case Structure. You can also specify a range for each case. The following example shows a pseudo code and its conversion to a proper LabVIEW code with Case structure. A Case structure (see Figure 2.9) has two or more sub diagrams, or cases. Only one sub diagram is visible at a time, and the structure executes only one case at a time. Figure 2.9. Case structure An input value determines which sub diagram executes. The Case structure is similar to switch statements or If...Then...Else statements in text-based programming languages. Figure Selector Label The case selector label (see Figure 2.10) at the top of the Case structure contains the name of the selector value that corresponds to the case in the center and decrement and increment 15

16 arrows on each side. Click the decrement and increment arrows to scroll through the available cases. You also can click the down arrow next to the case name and select a case from the pulldown menu. Figure Case selector Wire an input value, or selector, to the selector terminal to determine which case executes. You must wire an integer, Boolean value, string, or enumerated type value to the Case Selector (see Figure 2.11) terminal. You can position the selector terminal anywhere on the left border of the Case structure. If the data type of the selector terminal is Boolean, the structure has a True case and a False case. If the selector terminal is an integer, string, or enumerated type value, the structure can have any number of cases. When you place a Case structure in the diagram window, it comes with True and False frames that you can toggle by clicking the arrow next to the label. If Run button is broken. This indicates that the VI is not complete and LabVIEW cannot compile it. EXPERIMENT 1 : Create While Loop, For Loop, and Case Structure 1. In block diagram, Left-click Programming Structure While Loop/For Loop/Case Structure. 2. Click item While Loop/For Loop/Case Structure Left-click and Drag to the area that we want to create loop or structure. (See Figure 2.12) While Loop For Loop 16

17 Case Structure Figure 2.12 Create While loop, For loop and Case structure Create Array of Random Number using Loop 1. In Function click Structure For Loop Left-click and Drag to the area that we want to create loop. 2. In Function click Numeric Random Number and then put to inside of the loop. 3. In Front Panel Right-click Modern Numeric Numeric Indicator put to the Front Panel and then go to the Block Diagram move the Numeric Indicator to outer of the loop. After that, wiring the Random Number terminal with Numeric Indicator terminal. 4. Create constant in loop count terminal, then change the value to 6 (see Figure 2.13). The indexing point on the boundary is called a tunnel 5. Observe the different of tunnel mode. Figure Auto-Indexing in Tunnel 17

18 6. Create block diagram like in Figure If an array connected to the For Loop, then number of iteration depend on the number of that array element. If there are two array with different number element, then the number of iterations in accordance with the smallest number of array elements. Observe it! Figure Number of iteration of For Loop with Array Create Shift Registers Shift registers transfer data from one iteration to the next: 1. Right-click on the left or right side of a For Loop or a While Loop and select Add Shift Register. Or right-click an existing loop tunnel and select Replace with Shift Register, then click the other side of the loop to create the other half of the shift register. (see Figure 2.15) 2. The right terminal (down arrow/triangle) stores the data wired to it at the end of an iteration. The data goes up and around to the left terminal (down arrow/triangle) and is available at the start of the next iteration. 3. A shift register adapts to any data type wired into it and will change color accordingly. Up and around the loop Left terminal storing data from previous iteration Right terminal stores the result ongoing iteration Figure Shift register in For Loop 18

19 Shift register working principle can be seen in Figure Figure Shift register working principle 4. Create block diagram like Figure 2.17, then observe the output for each iteration. Figure Shit register with or without initial value Create Case Structure 1. In Front Panel Left-click Modern Numeric Numeric Control and Numeric Indicator, create both of them like in Figure In block diagram left-click programming structure case structure. 3. Programming Numeric Square Root. 4. Wiring the item of block diagram like in Figure

20 Figure Front panel and block diagram of square root value program 5. Then try to make a program to calculate Add and Subtract, Multiply or Divide (see Figure 2.19) Figure 2.19.A. Front panel and block diagram of Add and Subtract program 20

21 Figure 2.19.B. Front panel and block diagram of Add and Subtract program LESSON 3 : TIMER AND STATE MACHINE Flat Sequence Structure Consists of one or more sub diagrams, or frames, that execute sequentially. Use the Flat Sequence structure to ensure that a sub diagram executes before or after another sub diagram. Data flow for the Flat Sequence structure differs from data flow for other structures. Frames in a Flat Sequence structure execute from left to right and when all data values wired to a frame are available. The data leaves each frame as the frame finishes executing. This means the input of one frame can depend on the output of another frame. 21

22 1s 2nd 3rd Figure 3.1. Flat Sequence Structure Loop Timing in LabVIEW Normally when a loop, such as a while loop, finishes executing one iteration, it immediately begins running the next. It is often beneficial to control how often a loop executes, or its frequency. For example, if you wanted to acquire data in a loop, you would need a method to control the frequency of the data acquisition. Timing a loop also allows the processor time to complete other tasks such as updating and responding to the user interface. In the following figures, the processor usage for a simple VI with a while loop running untimed and timed are shown. Timing a loop can drastically increase performance. Figure 3.2.Untimed loop Figure 3.3.Timed loop Executing at 1000 Times a second Wait Functions After you create a loop, you can place a wait VI inside of the loop to control how long it waits before performing the next iteration. There are two basic wait functions in LabVIEW: Wait (ms) and Wait Until Next ms Multiple. Figure 3.4. Wait Function The Wait (ms) function forces the loop to wait for a user-specified amount of time, in milliseconds, before running the next iteration. 22

23 Example: Figure 3.5. Wait function example Loop would go to next iteration after 10 ms or more depending on amount of time the subvi takes. If subvi takes >10 ms, loop goes as soon as subvi is done If subvi takes <10 ms, loop goes at 10 ms mark. The Wait Until Next ms Multiple function watches the millisecond counter and waits for it to reach a multiple of the user-specified time, in milliseconds, before running the next iteration of the loop. You can use this VI to synchronize different activities. Example: Figure 3.6. Example Wait Until Next ms Multiple function Loop would go to next iteration after 10, 20, 30, or a greater multiple of 10 ms depending on amount of time the subvi takes. If subvi takes <10 ms, loop goes at 10 ms mark. If subvi takes 16 ms, then the loop goes at 20 ms. If subvi takes 22 ms, then the subvi goes at 30 ms. Tutorial: Implementing a Wait Function in a Loop Consider using one of the wait functions in a while loop. Using the information from previous tutorials, create a blank VI in LabVIEW. 1. Place a knob numeric control on the front panel by right-clicking on the front panel and navigating to Controls Modern Numeric Knob. 23

24 Figure 3.7. Numeric control on front panel 2. Change the knob s limits to 1 and 1000 by double-clicking on the knob s current limits and entering the new values. You will use the knob to control a while loop s wait time. Figure 3.8. Knob numeric control 24

25 3. Place a numeric indicator on the front panel by right-clicking on the front panel and navigating to Controls Modern Numeric Numeric Indicator. Figure 3.9. Numeric indicator 4. This indicator displays the while loop iterations. Figure numeric indicator display 5. Change the Representation of the numeric indicator to I-32 (long integer) by rightclicking on the indicator and selecting Representation. Click on I32. Figure Numeric indicator data type 6. Place a Stop Boolean control on the front panel. You can find this at Controls Modern Boolean Stop Button. Use this Stop button to stop the while loop. Figure Stop button 7. Double-click the name of the knob and change its name to Wait Time (ms). 25

26 Figure Knob numeric control name 8. Double-click the name of the numeric indicator and change its name to Iteration. Figure knob numeric control and numeric indicator display 9. View the block diagram by selecting Window Show Block Diagram or pressing <ctr-e>. 10. On the block diagram, drag a while loop around the front panel controls and indicator. Find the while loop at Functions Programming Structures While loop. Figure While loop structure After selecting the while loop, drag it around the three icons. If you miss one icon, just click and drag it into the loop. 26

27 (a) (b) (c) Figure While loop structure configuration 11. Wire the Stop control to the while loop s stop conditional terminal. Click on the right terminal of the Stop button s icon, drag to the left input terminal of the stop conditional terminal, and click to complete the wire. 27

28 Figure Stop control configuration 12. Wire the numeric indicator to the while loop iteration terminal. 13. Right-click on the block diagram to open the Functions palette and then navigate to and open the Timing palette, which is located at Functions Programming Timing. Figure Function palette 28

29 14. Place the Wait (ms) function, located in the Timing palette, inside the while loop. Figure Timing pallete 15. Wire the knob control Wait Time (ms) to the input of the Wait (ms) function. The knob value specifies how long, in milliseconds, the loop waits before running the next iteration. Figure Wait times function in while loop structure 16. View the block diagram by selecting Window Show Front Panel or pressing <ctr-e>. 17. Run the VI. Figure Command button 18. As the VI runs, change the knob value by clicking and dragging the knob; note that the speed of the loop, as shown by the iteration indicator, changes accordingly. 29

30 Figure Front panel display 19. Stop the VI using the Stop Boolean control. Figure Stop button 30

31 Using a State Machine (Event Driven) Architecture 1. Description A state machine is a programming architecture that can be used to implement any algorithm that can be explicitly described by a state diagram or flowchart. It introduces a way to create a program such that it responds to user events (such as key strokes and mouse events) or in-state calculation (such as comparing system variables). This architecture provides a distinct advantage over using a sequential architecture that uses data dependency to force execution in exactly the same way every time. Almost all programs that have more than a rudimentary user interface employ the state machine architecture they wait for an event (user interaction or calculation result), and then take appropriate actions based on this input. A state machine consists of a set of states and a case selector that determines which state the program transitions to next. In LabVIEW, a state machine is created with a while loop, a shift register, a case structure, and some form of case selector. The exact form of the case selector can vary, and will be discussed later. The while loop is the main program loop, and executes until the conditions for exiting the program are met. The while loop executes one case per iteration. The shift register keeps track of which case should be the next to execute (which is decided by the case selector code). Finally, each case of the case structure contains the action for one specific use action. Often, the default case is used as a timeout (i.e., if the use did nothing, check again to see if he's done something yet). Figure State machine configuration 2. Simple Example Here is a simple example that demonstrates the functionality and structure of a state machine. This example computes the cumulative result of simple arithmetic operations between the previous cumulative result and a constant. The arithmetic operation is decided 31

32 by the user through an enumerated control (enum). The value of this enum is what decides which case to enter in each iteration of the while loop. (a) (b) Figure State machine example This example doesn't make any determination of which state to transition to next based on any logic or code inside each state. The transition is entirely based on the value of the userselectable enum control. In the next section, we'll see how to expand upon this example to implement more complex behavior. 32

33 3. State Transitions There are many ways to transition between cases in a state machine. Which method you choose will depend on your specific application, needs, and preference. Here we'll discuss the different transition methods, and how each could be implemented in the simple example above. Default Transition A default transition causes your state-machine to behave as if you were using a sequential programming model, as there is only one possible state that occurs next. Use a default transition when you know that you want to do the same thing every time you exit that particular state. The default transition is usually used for a "Stop" state, because the only action that the user usually wants to happen in the stop state is stopping the program. Figure Transition state machine Select Function Use the select function to make a true/false decision to transition between two possible states. You can use the select function to take the result of a logic decision and output the appropriate state transition to based on that decision. We'll use the select function to transition from the "Divide" case to the "add" case if the cumulative output becomes too small (less than 1). Adding this transition to the "Divide" case effectively keeps our cumulative result from becoming excessively small. 33

34 Figure Select function state machine Case Structure The case structure case selection method is self-documenting and scalable. You can add as many possible transitions out of a particular state as you need to. One disadvantage is that not all of the code is visible at once, therefore the complete behavior of you transition code may not be readily apparent. The case structure is one of the most flexible transition methods. In this example, a case structure is used to determine which case to transition to next based on the value of the cumulative result: If the result is less than or equal to zero: Add If the result is between 1 and 500: Multiply If the result is between 501 and 1000: Subtract If the result is greater than 1001: Divide 34

35 (a) (b) Figure Case structure stat machine Transition Array The decision making code produces an index, which is then used to select the appropriate case from an array constant containing all of the possible state transitions. Figure Transition array state machine LESSON 4 : SubVI Definition Modularity, means to use modules or smaller parts for the overall objective. Within LabVIEW, program modularity means creating smaller sections of code known as subvis. SubVIs are the same as VIs. They contain front panels and block diagrams, but you call them from within a VI. A subvi is similar to a subroutine in text-based programming languages. Modularity refers to the ability to bundle functions in a manner that the internals of the function/subvi can be 35

36 altered/corrected/changed, but the change does not require other changes in other parts of the VI. In LabVIEW, a subvi is an example of a module. Figure 4.1 demonstrate the difference when replacing a section of code with a subvi. You can see the simplicity in the bottom figure. (a) (b) Figure 4.1. (a) Before using subvi, (b) After using subvi SubVI Icon When you create a subvi and use it, you see an icon within your block diagram that represents the subvi. You can customize this icon, which is the same icon in the upper right corner of the subvi front panel and block diagram. SubVI Icon default can be seen in Figure 4.2. Figure 4.2. SubVI default The functionality of the VI using: - Relevant graphics - Descriptive text - Create template for related subvis 36

37 Figure 4.3. SubVI icon Connector Pane You need to build a connector pane, shown as follows, to use the VI as a subvi. The connector pane is a visual representation of how inputs and outputs are connected to the subvi from the calling VI. Creating SubVI Figure 4.4. Connector pane location You can simplify the block diagram of a VI by converting sections of the block diagram into subvis. 1. Create a new VI and construct the following block diagram and front panel. 37

38 (a) (b) Figure 4.5. block diagram and front panel 2. Select the section of the block diagram you want to convert. Figure 4.6. Selection block diagram 3. From the Tools menu, select Edit Create SubVI. Figure 4.7. SubVI The selected section of the block diagram is replaced with an icon for the subvi. LabVIEW creates controls and indicators for the new subvi, automatically configures the connector pane based on the number of control and indicator terminals you selected, and wires the subvi to the existing wires. 4. Create custom icons to replace the default icon by right-clicking the icon in the upper right corner of the front panel or block diagram and selecting Edit Icon. You can also do this by double-clicking the icon in the upper right corner of the front panel. 38

39 Figure 4.8 SubVI Icon location 5. Window will pop-up the icon editor, in here you can change the picture by erase it and change with picture or text. Change the original picture with text, select Glyphs Choose the picture and drag to picture location. Add text, by select icon text fill the line 1 text. Then OK. Figure 4.9. Icon Editor 6. Double click to SubVI. Add Boolean control. Figure Front panel in SubVI 7. Use case structure to the blok diagram and wire like figure. 39

40 Figure Using Case Structure Define connections by assigning a front panel control or indicator to each of the connector pane terminals. 1. Right-click the icon in the upper right corner of the front panel. 2. Select Show Connector. 3. Select a different pattern by right-clicking the connector pane and selecting Patterns. Figure Choose the pattern 4. Once the connector pane pattern is selected, a. Click on a terminal in the connector pane b. Click on a control/indicator on the front panel 40

41 Figure Selecting connector pane 5. Go to main block diagram, right click on new connector create control 6. Use while loop, and then Run Figure Main block diagram Figure Adding while loop 41