Certification
Sample Exam Solutions for Review
@CsabaF wrote:
Hello there,
I have been working on my CLD preparation for a while and I think it´s time to post my first CLD sample exam solution.
It took 3 hours and 45 minutes to finish it (30 mins planning 2,5 hours coding and 45 minutes on documentation and clean-up).
I am not a native english speaker and I had a small problem with the specification. On page 6, first paragraph - what is the expected behavior when the selector is in "single" position? Did I understand it right and is my functionality correct?
I think my solution is far from perfect, but it works and I managed to finish it on time. 🙂
Any comments would be greatly appreciated!
Csaba
I would spend that last 15 minutes cleaning up your main VI even more. They are not going to be happy that you have wires running behind structures and all those crazy wire bends. You should also use other than the default labels for your controls. SInce you finished, you probably don't need too many style points, but why squander points away that you can pick up easily? I'm not sure how severe they will penalize you for those style issues, but you'll probably need about five style points.
About the possible misinterpretation: I think that if your code is well documented and executes as *you* said it should, you'll get consideration for that.
For instance:
"Requirement unclear: I interpreted this way."
And then go and code it that way.
@CsabaF wrote:
Hi Bill,
thank you for your quick reply, I really appreciate it!
Yes, I also noticed that my code looks a bit sloppy, but the last 15 mins would not have been enough to make a real cleanup. Some of that mess comes from a change in the logic made after one hour coding. I made a basic state diagram at the beginning, but I overlooked a small detail in the specs. 🙂
I will try one of the next samples tomorrow, I hope it will look better. I have to be more careful at planning, one bad decision there can easily ruin my whole test. :S
Csaba
I hate that. That's what killed me the first time I took the actual exam. One stupid brain cramp and I missed by 2 points. I'm re-taking it soon. Hopefully I will have clean run. 🙂
I would say that the graceful exit would be the first button case you work on. You want to make sure your application exits gracefully. I view this as a "standard" feauture and everything else is "optional." I think your app should initialize correctly and shut down correctly first, then attack everything else.
Check out the Queued Message Handler example for an even better way of exiting your app. Believe it or not, this may cost you in the style area as well as the functionality area since your implmentation of the design pattern departs from the template in a significant way. I'd say that your hard part will be getting enough style points to squeak by - which is okay. That's why style and functionality are weighted evenly.
Did you know that there is an output on the case structure selector terminal? You don't have to split up your error wire like you did in your sub-VIs. I'm not sure how much they will deduct on style points. It's not as bad as unbundling the status (which used to be standard practice, BTW, in very old versions of LV), but still you have unnecessary wire branches.
I see no error handling. THIS IS HUGE. To be sure, I Injected an error into your app where it reads the file and it fails to load the menus and just hangs there and there is no way to stop the app short of waiting for the timeout - and then there is no way to know what the error was because it was swallowed when the loop iterated. Error passthough only works if you have something at the end to catch the errors. Minimally, your app should gracefully exit upon error. With the limited time alloted, I would say it should be able to stop both loops and report the error. In the real world, you would output an error message to the ATM Meesage screen ("The ATM Machine has encountered an unepxpected failure. Please contact...") and then you would give the card back and the app would go into a non-accessible state (since you don't really want to drop to the operating system in this case). Developing error handling as one of your first steps really helps you in developing, too. If you have error handling, you immediately know where you screwed up. 😉
You definitely need to work on style. Pay attention particularly to 3b in your cld exam prep guide. You will probably need about 5 style points to get by, and I'm not sure you are there yet. Using a minimal amount of SubVIs can be devastating in this case. You end up enlarging your BD to the point that it gets too big for the screen and wires and stuff get misaligned in case structures that are invisible to you because LV is going to make space there, too. I'm not necessarily saying you should make more SubVIs because that would take away from your functionality time, but be aware that it's much harder to keep things neat without them.
That's all I can think of for the moment.
