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Jordan Kuehn

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Posts posted by Jordan Kuehn

  1. Hey guys

    I could use some help. Basically I have a vi that entered into a case triggered on a front panel boolean value change. However, this boolean is continually enabled or disabled and grayed out during the timeout case based upon a different controlling boolean. (a quick and dirty admin mode if you will).

    The operator claims that the button was grayed out the entire time and that the state was entered into without any action on his part after the subVI began to run.

    Any thoughts? I'm having trouble explaining why it got there.

  2. A custom windows environment variable could do the trick. Attached is code that I have used a couple times to see which machine it's on.

    J2ifr.png

    Keep in mind, LabVIEW will not see a new variable without being restarted.

    //Edit

    Not good if you're only interested in IP address obviously.

  3. Bitbucket looks great except for one thing.

    I can handle moving to mercurial, and I can even handle splitting my SVN repo into multiple by-project repos and simply organizing the repos into folders by customer. However, it looks like on bitbucket I have to place all of the repos at the same folder heirarchy level. That would force me to do something like [Customer_ProjectName] instead of [Customer]/[ProjectName]. Is there a way around this? I have too many projects to leave them all in a single folder.

  4. I have complained before about Error 6 but am still of the opinion that it is better than having files outside of the build.

    I would be nice if NI could do the build in a temp directory (as close to the root as possible) to avoid this, then copy it back to the dist location - all transparently (I currently have to use a script to do this manually).

    Care to submit to the Idea Exchange? I would love this feature. Often times when giving RT code to a coworker for testing builds fail because his folder structure is much deeper than mine. Building and deploying on the desktop before moving into the final destination is a complete PTA.

  5. I second crelf's questions and suggestions.

    I would also like to be able to turn on and off a power source, but am not sure this is possible as I haven't been able to find any really helpful text.

    Without knowing what kind of power source you are trying to switch, what load you are driving, and how fast you want to switch it, you can achieve this with a suitable relay and a single digital output line.

    If you have an ni motor controller for the stepper motor you mentioned you can likely find and example for it in the example finder in LabVIEW (Help->Find Examples...)

  6. I just got an email from NI that I passed the CLD exam!

    I've been poking around here for some time, but not really posting much though I'm sure that will change. There's not too many people in the world that know what a CLD is, so I figured I'd come share it here.

    • Like 1
  7. I just upgraded from 5 to 2010. I am using a P4 3Ghz PC with XP Pro. The intall (complete Full package) took about 6 hours on this machine. Then again, I installed it on my old laptop but just did the minimum and it was done in about a half hour.

    It is very slow to develop code with it now compared to 5 and 6. Selecting save as, for example, took 50 seconds before I got the file menu. The long times are not constant. Sometimes save can return the menu in 10 seconds or so. Pressing undo, I may as well get a coffee.

    VI's will run fine, then freeze for a second or so, then run for a while then freeze again. I found if I turned off the NI Webserver that it seemed to solve it. No freezes with a few hours of run time. I have not tried to restart the PC again and see of the problem returns.

    The new 3D graphs look very nice compared to the old ones but I was hoping to see a lot more modern looking controls in the library.

    I haven't experienced any of these issues you describe. Running LV2010 on both my desktop and laptop. Perhaps something is wrong with your machine.

    As far as modern looking controls, I find myself using the system controls a lot. They look nice in windows 7 and decent in XP. There's also a few controls suites in the package manager that are nice.

  8. Here's hopefully a simple question:

    What is the best method for communicating with an RT target with a Host controller (windows) that may reconnect at any time? Network variables, Remote Panel, Web Services, tcp, udp?

    I've used network variables and networks streams plenty, but network variables just don't seem reliable enough and network streams hang when connection is lost. Remote Panel and Web Services seem attractive due to the fact that everything is hosted on the target. I don't need deterministic control on the host interface, just a decent UI.

    Thoughts?

  9. As suggested earlier, post your code and we can be more helpful. Perhaps even a VI Snippet.

    tushar gave you good advice regarding timing when the trigger occurs.

    To further elaborate, if you are simply wanting the time from execution to the first threshold, you can place a tick count vi before your while loop. Place another inside the while loop inside a case structure that has the selector wired to the same boolean as what turns the LED on. In the false case you can put the put the tick count from the beginning. Then subtract the two and conditionally wire the result into a numeric indicator. When true you'll see the time between start and threshold, when false you should see 0. I have a feeling you may need a little bit more sophisticated approach, but this should get you started for now.

    • Like 1
  10. Here are my get/set temperature vi's for a Watlow F4 controller. You also need the NI Modbus library.

    getwatlowtemp.png

    setwatlowtemp.png

    And there seems to be an issue with the VI snippet. The clusters constants there can be remade and should have RTU and 1 as the values in them.

    Hopefully this is of some help to you.

    • Like 1
  11. I've recently picked up the JKI state machine and am really enjoying it. However, I have a (hopefully not stupid) question regarding the UI aspect of it.

    From what I see, the event structure only ever executes while the state queue is empty. In this event structure you put controls that you want to use to trigger new actions and other controls you put in a case to read as necessary? How then do you ensure responsiveness from one of the event controls if the state machine is off running for awhile through the queue? For example to have the program respond to a click of the built in 'OK' button and stop execution immediately rather than waiting an indeterminate amount of time while emptying the queue?

    Perhaps my thoughts aren't too well organized, but any pointers to discussions or just some advice would be great. I think what I'm after may be an asynchronous design and to move the event structure to a parallel loop? A simple example would probably speak a 1000 words here.

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