What are benefits of LabVIEW(Laboratory virtual instrumentation engineering workbench)?

Laboratory virtual instrumentation engineering workbench (or labview as it is commonly known) is a platform developed for designing systems and presents a development environment.

Benefits of LabView

1. Interfacing

- The extensive support that labview provides for access to instrumentation hardware is one of the key benefits of it. 

- In addition to the drivers, a number of abstraction layers are available for inclusion for a variety of buses as well as instruments. 

- These drivers and abstraction layers are presented as the graphical nodes. 

- A standard interface is provided by the abstraction layers so that communication with the other hardware devices could be established. 

- A lot of program development time is saved by the driver interfaces that are provided. 

- That is why people having limited coding experience of writing the programs can even develop programs and easily deploy the test solutions in a time less than what it might take with the conventional programming systems. 

- DAQmxBase is a brand new driver topology.

- It comprises mostly of the G – coded components having a few register calls via national instrument measurement hardware driver development kit (DDR) functions.

- It is known to provide hardware access that is independent of the platform. 

- This access is to instrumentation devices and a number of other data acquisition devices. 

- This new driver is available for the following platforms:

a)    Windows

b)    Mac os x

c)    Linux

- An interface for .net frame work applications is also provided by the labview using    which one can use XML files and data bases in one’s automation projects.

2. Code Compilation

- When it comes to performance, labview is at its best as it provides you even a compiler that can produce a native code for platform level of CPU. 

- Firstly, the graphical code is converted in to machine executable code by passing it through an interpreter and compiler.

- The syntax of the labview is to enforced during the code editing process only and then it is compiled in to machine level code whenever execution command is given. 

- The executable code is executed by the run time engine of labview which already has some pre-compiled code that can be used to perform usual tasks that have been already defined by the G – language. 

- Also, the compile time is reduced by the run time engine. 

- In addition to this it also offers you a consistent interface that can be used for a number of following:

a)    Operating systems

b)    Graphic systems

c)    Hardware components and so on.

- The code is made portable across the platform because of the run – time environment. 

- Labview code compiles slower than the equivalent code in C and this difference gets larger with the program optimization.

3. Large Libraries

- A large number of libraries with a large number of functions such as those mentioned below are provided with the labview package:

a)    Functions for data acquisition

b)    Signal generation

c)    Mathematics

d)    Statistics

e)    Signal analysis

f)     Signal conditioning and so on.

- The package also has a number of graphical interface elements. 

- The package has numerous advanced mathematics blocks which can carry out functions such as filters, integration and so on.

- Many other specialized capabilities that are associated with the data that has been captured with the help of hardware sensors. 

- In addition to all this, labview comes with mathscript which is nothing but a text based programming component having some additional functionality such as for mathematics, analysis, signal processing and so on. 

- This component and graphical programming can be integrated together via the script nodes and using a syntax compatible enough with MATLAB.

4. Code re use

5. Parallel programming

6. Ecosystem

7. User community

Explain LabVIEW (Laboratory virtual instrumentation engineering workbench)?

Laboratory virtual instrumentation engineering workbench (or labview as it is commonly known) is a platform developed for designing systems and presents a development environment. 

- The environment it provides is for the development of visual programming language from what are known as the national instruments. 

- The graphical language that is usually used is commonly known as “G”. 

- Make sure that you do not yourselves with G code.

- This graphical language had its release for the Apple Macintosh in the year of 1986. 

Labview is used for a number of purposes few of which are:

1. Data acquisition
2. Instrument control
3. Industrial automation and so on.

All these functions can be carried out on a number of platforms including:

a)    Unix

b)    Linux

c)    Mac OS X and

d)    Microsoft windows

- Labview 2012 which is the latest version of labview has been released recently in year 2012 in the month of August. 

- 'G' is actually a data flow programming language. 

- The structure of the graphical block diagram helps in determining the execution. 

- This graphical block diagram is actually composed of the LV source code using which the different function nodes can be connected via wires. 

- Variables are propagated by these wires. 

- Any node for which all the input data is available can be put in to execution immediately. 

- It involves a number of modes simultaneously, parallel execution is very much possible in G.

- Built-in scheduler is automatically exploited through multi–threading and multi– processing hardware.

- Multiple OS threads are multiplexed by the built – in scheduler over the nodes that are ready to be executed. 

- User interfaces called front panels are created by the labview and incorporated in to the development cycle. 

- The programs or subroutines of the labview are termed as virtual instruments or VIs. 

There are 3 main components of each VI namely:

1. A block diagram
2. A front panel and
3. A connector panel

- The third component i.e., the connector panel is used for the representation of the virtual instrument in the other virtual instruments which call this one. 

- Front panel comprises of the indicators and controls, thus allowing the operator to input or extract data from an active virtual instrument. 

- Another feature of the front panel is that it also serves as a programmatic interface. 

Thus, a virtual instrument can be run in either of the two ways:

1. As a program: The front panel serves as a user interface.
2. As a node on to the block diagram: The inputs and outputs for a particular node are defined by the front panel through the connector panel.

- Any of the virtual instruments can be tested very easily before it is embedded in to the main program as a subroutine. 

- Even non-programmers can take the benefit of the graphical approach since using it, they can build programs by just dragging and dropping the lab equipment’s’ virtual representation with which they have some familiarity. 

- Advantage is that the labview programming environment comes with documentation and some included examples which can be used to work out small applications very easily. 

- There is one disadvantage also which is that one might underestimate the expertise required from implementing high quality G – programming.

- Also, as far as complex programming or large scale programming is concerned it is a must for the programmer to have an extensive knowledge regarding the labview syntax and the topology it uses for the management of memory. 

- The advanced development system of the labview lets you create stand –a lone applications also.

What are the different types of Test Automation Frameworks?

Test automation frame work has got its own importance in the field of software testing. It can be defined as a set that consists of concepts, tools and assumptions that can be used to support the automated software testing. The basic advantage of using a test automation frame work is that maintenance costs are reduced by large margins. If any changes to the test case are made then there is a need to update only the test case files. No updates are to be made to the following two scripts:

1. Startup script and
2. Driver script

In some ideal cases there is no need of even updating the scripts in case changes are made to the application software. In order to have all the advantages of using a test automation framework it is important that you select the right one otherwise you will face the problem the other way round. 

There are various frame work techniques that are used namely:

1. Key word driven

2. Data driven

3. Structured

4. Linear

5. Hybrid and so on.

Purpose of Test Automation Framework

1. Defining of format for expressing the expectations
2. Creation of a mechanism for driving the application under a particular test.
3. Execution of the tests
4. Reporting of the results.

A test automation frame work consists of the following four components namely:

1. Test automation interface
2. Interface engine
3. Interface environment
4. Object repository

Types of Test Automation Frameworks

1. Ad-hoc test automation framework: 

- The scripting involved in this is developed in reactionary mode with the purpose of testing a single issue only. 

- The test case steps form part of each action script and exhibit low re-usability and call for high maintenance. 

- This frame work consists of some data inputs that are stored in the data sheet of the test script.

2. Data driven test automation frame work: 

- In this framework the scripts are considered to be an assembly of the function calls. 

- Data for the tests is supplied from the external source such as ODBC database, spreadsheets and so on. 

- Results are captured externally for each script separately.

3. Keyword driven test automation frame work: 

- A sequence of the key word prompted actions are used to be express the test cases. 

- Action scripts which serve the purpose of calling functions are executed by the driver script. 

- For this frame work no special scripting knowledge is required.

4. Model driven test automation framework: 

- This test automation framework makes use of descriptive programming for testing the dynamic applications inclusive of the web applications and sites. 

- The parametric code defines the objects and the work flow capabilities are enhanced by the custom functions.

5. 3^rd party test automation frame work like HP’s quick test professional: 

- This test automation frame work is also key word driven but its control is taken by the HP quality center data base. 

- It can be used in projects where there is a requirement for collaborative work efforts. 

- This framework has high level test requirements and the tests are defined as scripted components.

6. Intelligent query driven test automation frameworks: 

- This framework is object oriented and works on the agile principles. 

- It was constructed as a series of framework layers which compiles data at the run time with the help of data mining techniques which can be combined based up on the cope of the requirements of the test.