Help finish a 'simple' application

[RPJ]

I have SC 2345 as signal conditioning box. Then, I have SCC 6052E DAQ card. I have 2 signal conditioning modules for forces (3 channels for forces and 1 for voltage that is related to an engine's power) and I have 2 modules for 2 accelerometers. I have LabVIEW 7.1 Express and my operating system is Windows XP.

I am trying to build a simple application for acquisition of forces, power and acceleration (3 forces, 1 power, 2 accelerometers). I would like to start and stop my data acquisition based on a voltage (4.5VDC) that I am sending at the screw terminal (A11 and B12) of SC 2345. I have attached my files to this message.
The idea is to start the vi in the usual way (click on the little arrow) and then the vi should keep running without recording anything until the voltage is sent to the SC2345. When the 4.5 VDC reaches the SC2345, the vi should start recording the data and display it in charts. As long as the voltage keeps coming at the SC 2345 (terminals A11 for +4.5VDC and B12 for ground), the DAQ should continue. Once the voltage drops lower than 1 or 0.5 VDC, the data acquisition should stop and the vi should stop running. Optional, there could be a stop button to stop the data acquisition sooner than the voltage drop in case someone wants to do so.

NOW, I have built my tasks for forces, power and accelerometers using the NI-DAQmx, I have selected an example for the start and reference trigger based on external voltage, and I put all together according to instructions of a support engineer (over the phone). Recently I took LabVIEW BasicsI and II and I could further improve my vi. However, even the vi seems to be simple and easy to build, I still cannot get what I want.

For example - once I sart my vi, it imediatly stops with no error but without really recording anything. More than this, it does not wait for the incoming voltage to be triggered and then stopped when the voltage drops.

I feel that I am relatively close to a solution. However, I have to make this vi work in its rough form by this Thursday and I need some help to finish in time.

[jbrohan]

Hello
This is quite a large program for a first go out!
It stops most likely because you have the loop control of the main while loop set to False. (This is the feature at the bottom right of the while loop). If you pop up on it and create a constant the new constant is a F so it stops first time through.

There are lots of consultants (like me) who write programs like this for a living. We vary in our approach, but you could hire one for a few days to teach you what you need to know, or hire him to write the whole program and then you could study that and start your LV career with a good working program under your belt!!

Yours Sincerely
John www.tradersmicro.com

[RPJ]

John,

Thank you for taking the time to look over my program.

As for the hiring part, I thought about that but it is not an option at this time. Taking the training courses was supposed to provide enough info for what I will have to do. I'm sure each of the professional programmers like you did not start doing big time applications all of a sudden...

If you can help a fellow in need with a little advice or solution, that is really commendable and I appreciate you gave me some hint.

Meanwhile I am hoping there's somebody out there who can help a little more.

Sincerely,
Radu

[St. George]

I have a series of Vi's that have been developed for me.  Unfortunately my programmer has taken ill.  I am looking for someone who might be able to step in for a couple of weeks and finish some code at a resonable rate.

[altenbach]

You just added to a thread that is over two years old and deals with a topic completely unrelated to your post.

I would strongly suggest to repost this in the appropriate place, probably the LabVIEW Job Openings board . Good luck! 🙂

[Ben]

Hi St. George,

WARNING: Marketing pitch follows!

With the exception of the "resonable rate" part, that is exactly the type of work that I do. Some people get sticker shock when they see our rates.

But if you want the job done right the first time, it is very resonable. I have many clients that keep a PO open for us whenever they need new apps or changes to their existing app.

You can e-mail me at

bar@dsautomation.com

if you want to talk to us.

END of Sales pitch.

Otherwise, you can contact your local NI rep for developers in your area.

Ben