how to configure PZT control through R232 as COM4

[kingsgambit1943]

I believe i've configured all the NI hardware including: usb 6251 DAQ connected to a SCC-68 with a sg24 load cell conditioner.  Also configured a PI-PZT E-516 actuator as well through the  MAX series and parallel section.  The new cpu does not have a r-232 slot so Im using a usb-r-232 converter.  I therefore have it showing up as COM4, which is fine.  When I run the vi's associated with setting up and configuring the PZT I recieve NO errors, the settings are changed accordingly.  the problem is when I run my program the r-232 settings keep returning to COM1.  The program calls the PI setup function which ignores the user change of com1 to 4 and just changes it back when I run the program.  Any reasons why this is occuring?  How do you reconfigure hardware in association to a previous program ?  Is there any way to check if its the program or if its just my lack of configuration knowledge?

Thanks

[Dennis_Knutson]

Where exactly are you selecting the com port? I hope you're not opening a function in the driver and changing it there. That, of course, will not work unless you make it the default and save it. The correct place to set the com port is in the main program and pass it to the driver.

If that does not fix it, can you provde a link to this driver or attach it? Attach your code at the same time.

[kingsgambit1943]

Ive attached a manual about the program Im working with and the vi that is used at the beginning.  I think you are right on what Im doing.  Ive was at first just clicking on the sub vi and changing it there, however although it may be stupid I tried removing the vi  and replacing it with one I had saved else where with com 4 as default but that did not work either.  I get the warnings about opening from memory or from disk, I've tried both and both seemed to take me to same error.  when you mention The correct place to set the com port is in the main program and pass it to the driver.  How do I do that, it seems that would be a correct solution.  At first I thought the code reinitilizes the sub vi but I dont think thats the case

Thanks again

[Dennis_Knutson · Accepted solution]

In your main VI where you call this subVI, right click on the Interface Configuration input and select 'Create Constant'. Change the Com1 selection to Com4.

This subVI does not have com4 set as the default.