Tutorial number 1 on labview: Getting Started with LabVIEW: We are going to start a new series of tutorials on LabVIEW. We will start from very beginner level and by the end of this series you will be an expert of LabVIEW. We will be using LabVIEW 2015. In today’s tutorial we will cover following topics.
- What is LabVIEW?
- LabVIEW Interface and First Program
History of Labview
We come across different electrical systems in our daily life. In early days, systems were developed and they were controlled by humans. World is shifting towards automation with the advent of digital technology and user interaction with systems is decreasing day by day due to automation technologies. This also decreases the chances of human error in a particular task. All this has been possible due to different programming languages. As programming languages are developing, more sophisticated and smart systems are being manufactured. Following programming languages has been used with the passage of time to design a particular system.
- Machine Code (001011)
- Low Level Languages (Assembly, HDL)
- High Level Textual Languages (C, C++, PHP)
- High Level Graphical Languages (Simulink, Flow Code, LabVIEW)
Fig. 1: Programming Languages Timeline
According to above figure, as languages are becoming High Level; their performance is increasing. LabVIEW can be seen to be most high level language and hence is best in performance in terms of system design and its speed.
What is LabVIEW?
LabVIEW is abbreviated from “Laboratory Virtual Instrumentation Engineering Workbench”. LabVIEW is a platform and development environment for a visual programming language from National Instruments. Visual Programming Language lets user to create programs graphically by manipulating program elements instead of specifying them textually.In graphical language we need only to select different blocks and attach them in specific way rather ten writing thousands lines of code.Following figures can show the real power of Visual Programming Language.
Fig. 2: Comparison of graphical and textual languages
We can make designs, implement their prototype and deploy them to hardware using LabVIEW. Following figure shows different fields of systems that can be developed using LabVIEW. It reduces the development time by 4 to 10 times and has tools to acquire, analyze and present data.
LabVIEW in nutshell
Applications of Labview
Following are the key features of LabVIEW.
- Hardware Integration:
- I/O and Communication:
It connects to any instrument or sensor with built-in libraries and thousands of instrument drivers.
- Plug and Play Hardware:
It seamlessly integrates NI plug and play devices for USB, Ethernet, WI-FI and more.
- Advanced Built-In Analysis and Signal Processing:
- Built-In Analysis:
It accesses thousands of engineering-specific functions such as frequency analysis curve cutting and more.
- Inline Signal Processing:
It interacts with measurements and performs inline analysis in real time on acquired signals.
- Data Display and User Interface:
- Built in Controls:
It interacts with data using hundreds of drag and drop control, graphs and 3D visualization tools.
getting start video tutorial
LabVIEW Interface and First Program:
Having basic understanding of LabVIEW capabilities; now we will come to software part. In this section we will deal will actual LabVIEW 2015 software. We will see its interface and different controls available for different purposes.Before Starting remember:
- Block diagram execution is dependent on the flow of data.
- Block diagram does not execute left to right.
- Node executes when data is available to ALL input terminals.
- Node supply data to all output terminals when done.
- If the computer running code had multiple processors, two pieces of code could run independently without additional coding.
- Wires are used to transfer data between objects of block diagram. Wires are of different colors, styles and thickness depending on their data types. A broken wire appears as a dashed black line with a red “X” in the middle
- When we start LabVIEW for first time; following is the screen we come across. Two options are available
- Create Project (To start a new project from scratch)
- Open Existing (To open projects we have already created)
- Click “Create Project”. Following screen appears.
- Select “Blank VI” and click “Finish”. VI stands for Virtual Instrument. Following screens appears
- Front Panel (It is area where we place different graphical blocks for our design. It is user interface).
- Block Diagram (It is graphical source code. Data travels on wires from control terminals through functions to indicator terminals. Block executes by data flow.)
- Functions (It appears when you click on “block diagram” screen. It contains different control instruments for “block diagram”.)
- Controls (It appears when you click on “front panel” screen. It contains different control instruments for “front Panel”. It is not shown in picture.)
- Click on front panel and select “Booleans” from “controls” screen. This screen also contains many other options. We will explore them in further tutorials. For time being select “Boolean” which contain different devices for input and output.
- On selecting “Boolean” following screen appears.
- Drag “Push Button” and “Round LED” to “Front Panel”.
- Now click on “Block diagram”. You will see following screen.
- Bring the cursor near to the arrow on “Boolean” on Block diagram. A wire appears. Connect “Boolean” with “Boolean2” through wire.
- After joining both blocks through wire. Again click on “Front Panel” and press “”Run Continuously” button (the two round arrows) as shown in figure.
- Following screen appears when you press “Run Continuously”. Note the difference before and after pressing button. Above picture is before pressing the button.
- Now when we click on that is push the “Boolean” which is push button it turns the “Boolean2” ON which is LED.
- To stop running program and return to editable window press red round button i.e. “Abort Execution”.
- In this way, we can perform different functions on designs.
- The LabVIEW has such large number of function that it is impossible to remember function of every single control. To deal with this click on “Help” then on “show context help”.
- When you click “Show Help Context”. A dialogue box appears, which gives description of every element on which you hover the mouse pointer.
- To save the design, go to “file” and choose “save” or “save as” according to your requirement. Files are saved using “.vi” extension and projects are saved using “.lvproj” extension.
Now it’s your time to explore different functions of LabVIEW through this “Context Help” menu. Next time I will come up with another interested tutorial on Labview programming.