NI Training & Certification

Transcription

1 NI Training & Certification Certified LabVIEW Developer Exam Preparation Course

2 Agenda CLD exam process, format and scoring CLD exam objective and theme Design your way to exam success Preparation resources and exam tips Sample exam evaluations Questions

3 CLD Exam Logistics 1. CLD Exam Process 2. CLD Exam Grading

4 CLD Exam Process A PC with LabVIEW 2012 is provided Application development specification includes the following: Screen shot of Front Panel Description of the controls and indicators General requirements Functional specifications of the application LabVIEW documentation, Express VIs and examples may be used No external resources permitted Time allowed for exam: 4 hours

5 CLD Exam Grading Criteria Grading Criteria Points on Exam Percentage Functionality % Style % Documentation 10 25% Total Points % Passing grade is 75 % or higher

6 CLD Exam Objective and Theme 1. CLD Exam Objective 2. CLD Exam Theme

7 What skills does a CLD demonstrate? Problem solving skills LabVIEW competency Modular, scalable, and maintainable application design experience Consistent documentation Moderate-high development (wiring) speed Debugging and testing

8 CLD Exam Objective & Theme 1. CLD Exam Objective 2. CLD Exam Theme

9 CLD Exam Theme Scenario Sequencer Step 1 Execute: x secs Start Step 2 Execute: y secs Program design should be scalable to adapt to additional steps Step 3 Execute: z secs

10 Wait for k secs CLD Exam Theme Scenario Sequencer Step 1 Execute: x secs Wait for m secs Start Step 2 Execute: y secs Wait for n secs Program design should be scalable to adapt to additional steps Step 3 Execute: z secs

11 Wait for k secs CLD Exam Theme Scenario Sequencer csv or ini file Step 2,10,2 Step 3,4,3 Step 1,6,5 Start Step 1 Execute: x secs Wait for m secs Step 2 Execute: y secs Wait for n secs Step 3 Execute: z secs

12 CLD Exam Theme - Summary Exams are based on a sequencer type application Step order is configurable via an input file or user interface Timing is an essential aspect of the application Output or log file may be required Application must respond to user interface activity within 100 msec.

13 CLD Exam Design 1. Design Patterns 2. Timing Methods 3. Development Style 4. Documentation 5. Error Handling

14 Design Patterns for CLD Applications Design Pattern Advantage Disadvantage State machine Handles sequence control Cannot handle storing of sequences May not be responsive enough to user View interface events

15 Design Patterns for CLD Applications Design Pattern Advantage Disadvantage State machine Handles sequence control Cannot handle storing of sequences May not be responsive enough to user interface events Queue based user interface Event Handler View Extends state machine to store sequences Handles user interface events Does not allow intensive event or sequence processing User interface events need to be controlled by limiting access to front panel controls

16 Design Patterns for CLD Applications Design Pattern Advantage Disadvantage State machine Handles sequence control Cannot handle storing of sequences May not be responsive enough to user interface events Queue based UI Event Handler Producer / Consumer with Events View Extends state machine to store sequences Handles user interface events Responsive to user interface events Allows intensive event and sequence processing Does not allow intensive event or sequence processing User interface events need to be controlled by limiting access to FP controls Does not integrate non-user interface events well

17 CLD Exam Design 1. Design Patterns 2. Timing Methods 3. Development Style 4. Documentation 5. Error Handling

18 Timing Methods for CLD Applications Timing Type Timing Method Applications Execution timing control View Wait (ms) Wait Until Next (ms) multiple Regulate execution of state machine loop to allow other programs to run on the computer Execution timing control allows us to regulate how quickly a loop executes on the processor

19 Timing Methods for CLD Applications Timing Type Timing Method Applications Software timing control Get Date/Time in sec. Tick Count View Good general purpose timing method for timing a sequence operation. Encapsulate in functional global or SubVI Express Elapsed time VI View Measures Elapsed time with stop / reset control functions. Ready made solution!! Software timing control allows us to time a real-world operation to perform for a set time period.

20 Timing Methods for CLD Applications Timing Type Timing Method Applications Software timing control Get Date/Time in sec. Tick Count Express Elapsed time VI Good general purpose timing method for timing a sequence operation. Encapsulate in functional global or SubVI Measures Elapsed time with stop / reset control functions. Ready made solution!! Other useful Software timing control methods: Event Case Timeout Useful to stop an operation if no user activity is detected Synchronization VI Timeout - Useful for executing an operation at specific time periods

21 CLD Exam Design 1. Design Patterns 2. Timing Methods 3. Development Style & Documentation 4. Error Handling

22 CLD Application Style Small things that make a Big Difference!! Avoid the use of local variables when you can use a wire Use property nodes to modify control attributes and control values but not indicator values Typedefine reused enums and data structures Close references if opened explicitly Avoid data coercion and default tunnels Avoid copies of code - Develop SubVI if code is reused Create readable block diagram Avoid unnecessary bends, overlapping objects, wires

23 CLD Exam Design 1. Design Patterns 2. Timing Methods 3. Development Style & Documentation 4. Error Handling

24 Documenting CLD Applications Documentation Label wires to identify their use Label constants Example Description and tool tips for UI controls Block diagram comments VI / SubVI Properties» Documentation Tip: Brevity!!

25 CLD Exam Design 1. Design Patterns 2. Timing Methods 3. Development Style & Documentation 4. Error Handling

26 Error Handling in CLD Applications Stop VI on error when specified

27 CLD Exam Preparation 1. Preparation Resources 2. Effective Exam Preparation 3. Exam taking tips

28 Preparation Resources Browse to Enter CLD in the search Click on resulting link: On the CLD page, click on the following link:

29 Tips for Exam Preparation Test yourself: Time yourself through the sample exams Evaluate your solutions using the Exam Preparation Guide and the evaluation criteria given at the end of the guide Do better: Incorporate best practices in all your LabVIEW projects Use the generic sequencer model to develop new scenarios Improve your coding speed Find optimal ways to solve problems in LabVIEW

30 Tips for Exam Take a few minutes to plan your application Decide on the best main VI architecture for the application Decide which modules / SubVIs you will need to create Decide on the timing method Focus on getting most of the core functionality working Document the VI and SubVIs Clean up block diagram towards the end Pace yourself Time passes quickly when you are having fun!!

31 What happens after the exam? Exam proctor transmit exam project to NI for evaluation Candidates receive results in 4 weeks Exams are evaluated by two engineers Successful candidates receive CLD shirt, logos and certificate by mail CLDs must recertify every two years or certify as CLA Unsuccessful candidates can improve on the feedback given on the evaluation sheet Re-attempt the exam when prepared

32 This concludes the CLD Preparation part. Thanks for attending the CLD preparation course Best of Luck on your CLD exam!!! Questions / Comments?

33 Other Resources LAVA forums Darren Nattinger s practical tips on CLD readiness

34 This concludes our session. Thanks for your interest in the certification program If you need assistance, please Best of Luck on the exam!!

35 Sandra s Slide on CLD Prep Day

36 Execution Timing Control Return

37 Software Timing Control Using Functional Global Functional Global Using Get/Date Time In secs function Return

38 Software Timing Control Using Elapsed Time Express VI Elapsed Time Express VI This is a subvi from the Car Wash sample exam Return

39 Certified LabVIEW Developer Preparation Day Item Time Registration and coffee Preparation for CLD exam Sample CLD exam (4 hours) Lunch Feedback on exams and sign up for certification dates Next date: Friday 18 th October 2012 Presented by and feed back from a CLA 43