LabVIEW CLA Complete!

That’s the first tick off the 2014 Action Items list we can now make – CLA Complete! We’ll go more into depth with that list in a future post, but at this moment I’d like to provide those who are considering taking the Certified LabVIEW Architect (CLA) examination with some insight and guidelines for the examination. Without knowing my results for at least the next four weeks, I’m hoping to have provided National Instruments with what they were looking for when grading these examinations. Nothing wrong with being cautiously optimistic! 

At the time of this article (09/02/2014), the CLA examination is graded based on the following criteria:

• User interface and block diagram style : 10 points
• Documentation : 20 points
• Requirements coverage : 30 points
• Architecture development : 40 points

The most challenging part of the entire examination is <<<TIME>>>. I cannot stress this enough. As it’s been mentioned throughout the NI Community, architecting an application in four short hours is extremely challenging. It is a common mistake to begin implementing algorithms for certain sections of the examination, when that is generally not required. It is not expected to have a fully functioning application, although you probably don’t want to have any broken wires. I feel I spent far too much time with icon panes, inter-process communication technique and re-reading requirements on the examination. Much of the time, all that is required is creating a VI, labels to cover requirements and how those requirements plan to be covered.

What I can say is that the actual exam was very similar to the sample ATM examination, which can be found in the NI Certified LabVIEW Architect Exam Preparation Resources section. In fact, my proposed architecture was very similar to the ATM Solution, of which the top-level Simulation Interface block diagram can be seen below.

CLA ATM

ATM Solution Block Diagram

 LabVIEW now comes with various architecture templates, which I highly recommend you make use of. Those include the Finite State Machine, Queue Message Handler, Producer/Consumer (with Events) and Actor Framework. I would recommend that the architecture you choose should be one that you are completely comfortable with, which will also achieve the requirements outlined in the CLA examination. For example, if response to GUI events is time-critical, perhaps it may not be the best idea to use a Finite State Machine (unless you will use it with parallel loops).

Another important concept is interprocess communication. Determining which method you will use to communicate between processes is extremely important. Here are a few ideas you may consider:

  • Queues with Command & Data Clusters (Many-to-1 relationship)
  • Notifications (1-to-many relationship)
  • Global Variables (avoid if possible)
  • Functional Global Variables (LV2 Singleton FGVs)
  • Data Value References (DVRs)
  • TCP/IP Network Communication
  • VI Server

I decided to architect my application similar to the method which was used in the ATM solution. I have also heard of others who have used LVOOP and the Actor Framework. There were times I was covering requirements without even realizing and perhaps I didn’t drop the [Covers :REQ123] label down. Some marks will probably be deducted off there. Also, when time was at near its end, I started dropping down requirements coverage labels everywhere I think they should be located.

Equally important is how you still structure your application. That is, will you have Virtual Folders similar to the ATM Solution? Will you create separate LabVIEW Libraries (lvlib) files, with private access scoped VIs? If using LVOOP, what will the access scope be of particular subVIs within your class?

For any of you thinking of going for your CLA Certification, I wish you all luck, but I highly recommend you study and feel comfortable with architecting full applications in LabVIEW.

In other news, my China Visa has now been processed and I’m ready to go! Strangely enough, this will be my first time traveling to China, despite having been to multiple global OEMs and Contract Manufacturers. The new mandate will kickoff tomorrow and I’ll be on a plane shortly!

ChinaVisa

Single-Entry China Visa

LabVIEW CLA Complete! was last modified: May 2nd, 2014 by Paulo R

Comments

  1. Hi Paulo,
    I just read this post, and I agree with your advices.
    The fact is, can you tell us what were the NI comments on your CLA ?
    I guess you failed because you’re always on the CLD list and this post is dated from 9 February.
    I take the exam this friday, and your way of thinking the CLA is really closed to mine, so I’m quite bit worry…

    • Hey!

      You are correct. I did not pass my CLA examination. I scored 66.4%, missing the grade by 3.6% However, two colleagues in my industry also took the examination around the same time and they both passed. Don’t sweat it. Just be ready!

      While the examination was not extremely difficult, the main concern is always timing. If you’ve practiced the sample examinations on NI’s website, along with timing yourself, you may be ok. It also wouldn’t hurt to take NI’s training courses or have another set of eyes to look over your solution for the practice exams.

      I’ll be retaking this examination sometime early 2015. This time failure is not an option :)

      Good luck!

      Paulo

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