Certification
Car Wash REVIEW
Overall, I think you did well on this exam. Did you complete it within 4 hours? If so, I think with a little more practice you will pass the CLD exam! Here is what I noticed:
Documentation
1. Looks pretty good!
Style
- The unititalized shift register (USR) for the Wash Options wire is dangerous. This retains values if you stop and restart program. Granted, new values are written into that wire by your "Wash Options.vi", but I'd strongly recommended initializing this shift register so that you know what value it contains at start up.
- Put major functionality in SubVIs. Examples are the Time and Reset states. Making code modular is important for passing the CLD and it makes debugging easier. This is because you can test the code as modules.
- In your project manager, don't auto-populate your "Car Wash LV 2012" folder. This puts the test specification document and two project files in the project manager that aren't really needed. This makes the hierarchy in in the project manager feel cluttered. In your case you only need the Controls folder, SubVIs folder, and "Car Wash.vi" file in the project manager. If you feel you need your documentation in the project explorer use a virtual folder labeled "Documentation".
Functionality
- I'm nervous of two arrays being autoindexed in one For loop in Select Wash.vi. If these arrays are not the same size, then it will only iterate the for loop as many times as the smallest array being autoindexed. This can cause bugs that are hard to identify.
- Consider learning how to use the "Ellapsed Time.vi" express VI. I always thought this VI was hard to use, but I decided to learn how to use it the night before my CLD exam. Learning how to use it and using it during my CLD saved me a good 20 minutes during the exam. Of course, practice making your own timers, but =this express VI is very good to know how to use!
- When the vehicle exits the wash the slider didn't reset to "Entry". Once the slider goes to Exit and everything else resets the car position slider value should be at Entry, not at Exit. The problem you are facing is by the time the user moves to Exit position and then lets go of the control via the mouse the initialize case has already happened. But since the user is slow compared to that case executing, the slider gets left at the Exit position.
You are getting very close. A little more practice and I think you will be ready to take and pass the CLD exam!
You're right... There isn't any easy way to pause the Ellapsed Time.vi. 
I thought abut this for awhile, but didn't see any easier solution to pause the timer in your code...
@zenthoef wrote:
You're right... There isn't any easy way to pause the Ellapsed Time.vi.
I thought abut this for awhile, but didn't see any easier solution to pause the timer in your code...
Actually the edit to the Express vi is fairly straight froward. (A trick any potential CLD might wish to learn
)
The version you posted adds the elapsed time to the target time on each paused iteration and doesn't automatically reset, this one is not so straight forward but works as expected:
