I am finding that it is hard to develop really useful applications when doing one-off projects where a customer writes a one or two page requirements document and wants an application to meet those requirements. Hence, my focus these days is doing specific applications targeted to a given field or clientele. Currently these fields are Geotechnical Materials Testing Informatyion System (MTIS) also known as LIMS (Laboratory Information Systems) and Measurement While Drilling Applications & Logging While Drilling Applications (MWD/LWD). A link of GUI for these is available here.
. . . if anyone knows a party who may be interested in these types of applications we can communicate further.
I have a pretty simple issue. I want to be able to change the value to a ring, exit the VI completely and open it and run it again with the initial value of that ring being the one that I had previously changed to.
How would I do that?!! I know that with an Invoke Mode, I can reinitialize the ring to the default value. But that's not what I want. I basically want to change the default value of the ring during runtime, so that when I use the VI at another time, I can start the program with the ring having a different value.
I have a chart that displays my load and indicators stating the current load values from test lab equipment. I've been asked to have my program also display ramp loading, so basically i have to chart the rate of change of the load. Can I some how graph the rate of change, or difference between a value and it's previous value?
Last post made by: Gavin Burnell on Jul 4 2008, 09:43 PM
I have noticed something strange while developing some code for ni usb6009 (this same behavior on 6501). I want to load some digital patterns using digital i/o's. I dont really mind that samples are flushed out quite irregular (software timing) but there is one condition for which this module acts quite weird. It seems that when samples on any line are not changing their states, they are either ignored or flushed very fast (I dont know which is true). I hope example below will make it clearer.
I trigger the scope with P0.4->channel 1 on the scope.
This is what I am sending:
This is what I am getting on the scope (1->P0.4, 2->P0.3, 3->P0.2, 4->P0.1)
Than I push the trigger 4 clocks further:
And result is exactly this same as before.
Here I put trigger sooner when something is happening on the lines
And it works fine:
Did anybody came across problem like this?
Below is the code I am using to send the waveform. I have tried to replace waveform with 2d Boolean and send each bit in separate 'for loop' iteration but it didn't help.
Thanks for help,
Krystian
Last post made by: kristos_b on Jul 3 2008, 09:17 AM
I'm the student from Kasetsart University of Thailand.Now, I want to make the robot and use the labview to control my robot.But now,I don't know anything about the labview but I want to use it. I hope everyone on this site can help me. I don't have anyone to help me here. If who have the suggestion and the knowledge to teach me,please contact me on k_poom@hotmail.com I'm waiting for you. Thank you.
I'm the student from Kasetsart University of Thailand.Now, I want to make the robot and use the labview to control my robot.But now,I don't know anything about the labview but I want to use it.
firstly, im stil new to LabVIEW actually...hope someone can help me out with my assignment recently... thanks a lot for those who willing to help.. im trying to use the DAQ USB6008 to simulate a 16 x 2 character LCD display. im using LabVIEW 8.5... can anyone teach me how to simulate the LCD using LabVIEW and the DAQ USB6008 ?
I want to save images directly to the hard disk during acquisition at a frame rate of 30fps. Although, this is a reasonable, not very high frame rate, im not achieving the frame rate im asking for. The maximum that i can get is about 14fps for 582x782, 10-bit images and an Ultra-320 15K RPM SCSI hard drive(which is empty; the OS is on another HD). According to my calculations, i should be able to easily save frames at 30fps, as all i am requiring is 17MB/sec, even if we assume that the bus speed is slow. I am sure that there is something wrong going on. Could anyone please give me some advise or suggestions as how to fix this?
Using: Cohu 7700 Camera Link PCI-1428 Labview 8.5.1
I've created a new category in the Gallery called LabVIEW User Interfaces. Please create your albums and post images there of your LabVIEW masterpieces. I've also created a sub-category of bad and ugly LabVIEW UI's as an example of what NOT to do. I've moved two existing User albums into this new category as a starter. I hope to see more UI's here in the future.
Have Fun!
PS: Should we create a category for really huge or messy LabVIEW diagrams?
This morning LabVIEW 7.0 will not run on my (Boot Camp) Win XP machine because the license has "expired", but the license manager utility lists the license as never expiring! (See attached screen shot.) It ran fine last week. It runs fine on another XP machine with the same licensing. Anyone got any idea what's wrong and how to fix it?
Last post made by: Gary Rubin on Jul 3 2008, 05:26 PM
Should I break out controls and indicators as unique child-classes under Boolean?
I have the following class hiarchy.
Brief explanation;
Plug-ins - This class defines all objects I will be able to drop on the FP while the app is running.
Dynamic - All objects that will change while the app is in Operate mode. These will be controls and indicators.
Static - These will be background decorations and anything that has an image that does not change.
Boolean - All dynamic objects whos value is either 1 or 0.
LED - A round LED.
Toggle PB - Round push-button
Toggle SW - A toggle switch.
Since the LED class will not be something the user can click on (I'm trying to simualte the real world not re-write LV) it will not have to support a "Mouse Down" method. The "Toogle PB" and the Toogle SW" will have to support a Mouse Down method.
Does this observation indicate I should create two intermediate classes under Boolean "Control" and Indicator?
Let your comments fly, I am trying to learn with this project so your comments and suggestions are welcome!
I am developing my first LVOOP app and I can't find an option to copy or duplicate a class. In this app I am attempting implement the Holy-Grail of LV, create controls and indicators on the fly. All of the controls and indicators will be individual LVOOP classes and so far, I have the following class hiarchy.
Brief explanation;
Plug-ins - This class defines all objects I will be able to drop on the FP while the app is running.
Dynamic - All objects that will change while the app is in Operate mode. These will be controls and indicators.
Static - These will be background decorations and anything that has an image that does not change.
Boolean - All dynamic objects whos value is either 1 or 0.
LED - A round LED.
Toggle PB - Round push-button
Toggle SW - A toggle switch.
WEll it turns out that there is very little differnce between "Toogle PB" and Toogle SW" aside from the images associated with true and false. What I would like to do is right-click on the "Toogle SW" calss (in the project window) and select Duplicate class. But that option does not exist.
So far I have had to manually create the new class and then set all of the options and inheritances manually.
If there is no official way to do this, how do others go about cloning a class?
How would you do logistic regression in Labview? Some key points (see the wiki link for more detail), where f(z) is a probability function for some event:
The variable z is usually defined as
where β0 is called the "intercept" and β1, β2, β3, and so on, are called the "regression coefficients" of x1, x2, x3 respectively. To find the parameters βi, one optimizes them such as to obtain the maximum likelihood of getting the actual observed data. Making a few semi-reasonable assumptions, this amounts to maximizing
where L(theta) = the likelihood of getting the observed data, and L* is just the log of that.
Why use this approach? In my application, I've got a few categories of scrap metal that I'm trying to sort, let's say Al, Mg, and Zn. They're on a belt, and several diagnostic tests are done as they whiz by; each test outputs one or more real numbers. No one test is absolutely decisive, thus the need for optimizing their weightings.
I'm thinking of negating L*(theta) and using Conjugate Gradient nD.vi from the optimization palette. Does anyone have experience with this type of problem, and want to offer advice? If you thinking I'm barking up the wrong statistical/optimization tree, I'd like to hear your thoughts on that too.
Can anyone help me retrieve the number of samples that gets set in the Simulate Signal Generator? I use this value elsewhere in the code, and I would prefer not having to update constants all the time. Thanks in advance.
Mark
Last post made by: Karissap on Jul 3 2008, 10:25 PM
Well after a lot of research I still have not found a way to use the fuzzy logic toolbox by MATLAB in LABVIEW. Essentially I have DAQ and actuators being recieved/controlled in LABVIEW, but I'd like to offload the AI to MATLAB. Is there any simple way to do this? Perhaps a link to previous posts? I thought Simulink could provide my solution but it appears that LABVIEW will create an interface for MATLAB controls. Any other solutions?
Thanks in advance, Mark
Last post made by: PhattieM on Jul 2 2008, 01:23 PM
I have a piece of software that outputs a *.csv file.
One column of data is of the form "Wednesday 2nd July 2008 12:05:00"
The software has a very basic user interface and I cannot change the time/date stamp. Furthermore, the time/date stamp is only recognised as text after it saves, and not as a stamp that I can change (in Excel for example).
I have been trying to write a program that can read this text (date/time) and remove the "Wednesday 2nd July 2008" segment.
My thinking was along the lines of.... Read spreadsheet (*.csv file), isolate the column with the text then remove everything before the time, thus cropping the data.
At the moment I can read the data into an array (of numbers) or into a table (of numbers), but I cannot disply the text, hence do anything with the text.
Can anyone suggest a method of producing the *.csv values but not simply numerically?
Thanks
EDIT: I just noticed I told the "Read from Spreadsheet" vi to read Double, not String. Problem solved.
http://www.geocities.com/old_electric_cloc...ortt-178-kB.htm This beautiful animation show us an astrnomy clock with a master clock and a slave clock. The question is how does it work ? what is the purpose of the string on the slave pendulum. I believe that it is all about energy conservation and phase. I feel that the same idea could be used elsewere. Jason
Last post made by: JasonXCX on Jul 2 2008, 10:49 AM
Hi.... My project has many(500 to 800) controls and indicators which are spread over many individual vis. I wish to control all these vis from a single (main) vi. I am using "call by reference" technique, which is the best way (I hope !!). To handle these controls easily I'm using clusters. I shall control this main vi from Python. I know how to access each individual LabVIEW control terminal from Python. I kept all these control and indicator terminals in side clusters. Now, I'm able to read and write whole cluster at a time, which is not my requirement. I want to read or write only one cluster element at a given time. I tried a lot but I'm unable to work it out. Pls...help me to solve my problem. I have one more doubt, Instead of keeping all controls and indicators in main vi directly, I'm simply merging into clusters. This merging process (into clusters) takes place in individual vis. Is this step increses/decreses complexity of model ?? We want to keep the code as less complex as possible.
Thank you,
Ravinder
Last post made by: jpdrolet on Jul 2 2008, 01:27 PM
Anyone got any idea what's wrong and how to fix it? 
where β0 is called the "intercept" and β1, β2, β3, and so on, are called the "
