A driver for MKS PR-4000 via serial port

[Karl T.]

I did select auto parse, and it said that it had two outputs (giving the exact numbers from the instrument that I've been questing for all this time), as I wanted, but then I closed the configuration window, and the object in the block diagram had no inputs or outputs, and couldn't be converted to a VI that has anything in the block diagram. It seems like something is broken. Any ideas what is wrong? Could I be missing some software?

[unclebump]

I found a manual that describes the serial communication in chapter 8.

http://electronique.lal.in2p3.fr/docs/Virgo/valves/generic/docs/PR4000Manual.pdf

[Karl T.]

Hi unclebump,
Thanks for the pointer. Oddly enough, that set of commands doesn't seem to work for the device I have. In the manual that came with the device there is another set of commands that seems to work. I can extract data from the instrument, and the numbers I want appear in the Instrument I/O Assistant Express VI setup window. Then I close the window, and I believe that it should give me outputs from the express VI icon in the block diagram. It doesn't.

All of the tutorials I've seen have relied on it producing some sort of output there, but it doesn't. Since I can now communicate with the device, and get the numbers I want to show up on the computer screen, it seems that the problem is a LabVIEW software problem, no longer a hardware problem. (That sounds like progress to me!)

How do I get some output from the Instrument I/O Express VI?

[unclebump]

Can you give us a screenshots of the config inside the instrument express vi??

[Karl T.]

Good idea.  Here are a couple of screenshots, along with a description of what I did (I hope this helps):

step1.jpg
I placed the Instrument I/O Express VI into a blank block diagram, and it came up with this dialog, I selected COM1, and added a "write and parse" step.  The step gives the command to get the data, and then recieves it, and parses it to get the big red number in the lower right.  That is the number I want.  I think it should give an output, in the lower left it lists the outputs, and there are two (I'm after two numbers from this device, the other one displays in the same way). 

So, I clicked OK, and went back to the block diagram.  All I see is the picture in Step2.jpg, which is the Express VI, but there are no outputs, even if I try to expand it, right click on it, etc. 

Have I missed a step?

Thanks again for your help!

[MichaelChaney]

If the Express VI is not generating the code when you click OK, then there might be something wrong with your installation of the IO Assistant.  I also noticed that you are using an older version of the IO Assistant.  You might want to contact your sales representative and get a copy of the latest NI Driver CD, which includes the latest version 2.0 of the IO Assistant.

[Karl T.]

I tried on another computer here, which seems to have a different version of the express VI, but also has the same problem.  Here is a screenshot of the other one, is this the more recent version of the I/O Assistant?  It is very possible that the software is installed wrong, I'm looking into that.

[MichaelChaney]

This other IO Assistant definitely looks like version 2.0.  Since you have two different versions on two different machines, it's unlikely this is an installation error.  Then only way I was able to reproduce an IO Assistant with no code was to click "Cancel" or the big red X instead of clicking "OK".

After adding your steps and clicking the "OK" button, do you see a progress bar that says "Generating Code"?  If not, then maybe this is an installation error.

[Karl T.]

Yes, it does seem like a problem with the installation. It just doesn't want to give an output, and doesn't say it is generating any code ever. We're going to try it on a few different computers to see if the istallation is any better on those, and I'd like to try reinstalling LabVIEW again, but I'm not in control of the installation CDs.

I've also tried creating my own LabVIEW code without the assistant, but with no success. I may find and attach a screenshot of that also.

[MichaelChaney]

See if a reinstallation helps.  Also, make sure that you are clicking "OK" and not "Cancel" or the big X when finnished setting up the wizard.

If you are having trouble creating your own LabVIEW code, there are a few serial examples in the NI-Example Finder.  From LabVIEW, go to Tools >> Find Examples... and search for "Basic Serial Write and Read" or "Advanced Serial Write and Read".  These examples can be used to model your own code after.