how can i save control's parameters or values on the front panel so i can call it back when in need??

[alfredo_2k2]

I built a program for dynamic signal analyzer by using LabVIEW 7.1.

I want to develop this program so i can save the control's parameters or values for any spesific need and i can call it back when i need it or load it. It is kinda like saving measurement parameter. Please help me. Thanks.

[Jeff_T.]

There are several ways that you can accomplish this, based on when and how often you want to save the values.  The simplest thing is to select Operate > Make Current Values Default but if you want three different control "scenarios" that you would like to call upon, then you will need to save those control values to three different files.  When you want to load your control values, just load a file, read the values and send the values to local variables that are linked to your controls.  I have attached a document and example code that help demonstrate this technique.

Tutorial:  Remembering Control Values

Example Code: Saving and Loading Front Panel Control Configurations

Good luck and let me know if you need anything else!

Regards,

Jeff Tipps
Applications Engineer
National Instruments

[alfredo_2k2]

thanks 4 your suggestion but i unfortunately cannot save or open the example code u gave.

could u like to send it again??

thanks.

[Jeff_T.]

alfredo,

I apologize, please try this link for the example program that I mentioned above.

Regards,

Jeff

[alfredo_2k2]

thanks mr.Jeff for your example code... it already work out... very nice...

but i have two other questions here....

first of all, in my program, exactly in trigger facility, my pretrigger control can affect very well for continuous signals, but transient signals. can you give any information about this?? 

the second, my PCI4451 have 2 analog input channel (through BNC-2140 Connector Accessory), but actually in real time experiment i had done, i found that the 2nd channel generate bad signal (too big distortion), can you give some explanations or suggestions for me??is there something wrong in the BNC or in the PCI card??

best regards...

Message Edited by alfredo_2k2 on 09-06-2006 03:40 PM

[Jeff_T.]

alfredo,

I'm glad to hear that your code is working.  With regards to your 4451, if one of the channels seem to be malfunctioning then try switching the signals from channel 1 to channel 2.  If the distortion stays on channel 2, then there could be a problem with your PCI card or BNC connector.  If you make the switch and the distortion changes to channel 1, then the problem is probably in the signals themselves.  Try switching the channels, if the problem seems to be with the hardware then we can try to narrow down the problem between the BNC connector or the PCI card.

With regards to the triggering question, could you please explain the problem again?  I need to know a little more about what you are trying to do before I can make any suggestions.  Thanks in advance for your reply.

Best Regards,

Jeff Tipps
Applications Engineer
National Instruments

[alfredo_2k2]

mr.Jeff, i have tried your suggestion to do switching, and the fact is actually bad signal only happen at channel 2. So, how can i know whether the problem sources come from BNC connector or PCI card??haw can i fix it??

about the triggering, this is additional information...

i have a program based on LabVIEW 7.1 for dynamic signal acquisition, i built triggering facility inside. In the trigger setting, there is pretrigger control which is become malfunction if i input transient signals, such as exciting the structure with impact hammer...but if input continuous signals, no problem is found. I don't know why this problem occur, please give suggestion or maybe another example code to solve this problem... thanks a lot.   

[Jeff_T.]

If you have another 2190 or 4452 that you could swap out, that would tell us alot.  If you don't then the only way to narrow down the problem is by bypassing the 2190 and wiring your signal directly to the 4452.  This might take a little creativity on your part but the pinout of the device is in appendix B of the user manual.

PCI-4452 User Manual

I don't know if the triggering issue is related to the increased distortion that you are seeing or if it has something to do with your code.  There are three important questions that I have about your application.

1. How long is your transient signal above the analog threshold that you specify? 
2. Which channel are you triggering off of? 
3. Are you using hysteresis?

Best Regards,

Jeff Tipps
Applications Engineer
National Instruments