NI_VISA

[Devteck1]

Hello and let me thank anyone who might be able to help me.

Fisrt I was trying to follow the example in this link http://www.ni.com/example/29925/en/ to set an sequence that basically is a Serial port that may be reused by many different projects. When I follow the read me doc in the zip file I get alot of errors. Now I.m not sure if this is due to version incompatability or I'm missing something all together. The TestStand  Engine Ver is 2013(5.1.0.226) then Sequence Editor Ver is 5.1.0.226. Again any help would be aprreciated.

[Devteck1]

I think the issue is with these steps because I'm not sure if I should be putting these in the exact folders listed because the do not exist in eithe folder.

HOW TO INSTALL VISA STEPS:

1. Unzip the Files to <TestStand Folder>/Components/User/StepTypes/VISA

2. Copy the Install_NI_VISATypes.ini

from <TestStand Folder>/Components/User/StepTypes/VISA

to <TestStand Folder>/Components/User/TypePalettes

3. Copy the VISA.ico

from <TestStand Folder>/Components/User/StepTypes/ VISA

to <TestStand Folder>/Components/User/Icons

I have the following location for this 

C:\Users\Public\Documents\National Instruments\TestStand 2013\Components which hase no user folder

and 

C:\Program Files (x86)\National Instruments\TestStand 2013\Components which also has no user folder.

any info would be helfull. Thanks.

[Daniel-E]

Hey Devteck1,

In newer versions of TestStand, the User folder was removed from the TestStand directory. To replace it, we created a TestStand Public directory, located at C:\Users\Public\Documents\National Instruments\TestStand <version> as you mentioned. You should be able to unzip the files to the listed folders in <TestStand Public>\Components. For example, the step files will go in <TestStand Public>\Components\StepTypes\VISA, andthe NI_VISATypes.ini will go in <TestStand Public>\Components\TypePalettes.

I hope this helps, and let us know if you run into any more trouble with it!

[Devteck1]

Thank you Daniel-E for responding, I followed your instructions and I am still getting the following errors and do not know what they mean or how to solve the issue. Again thanks to anyone who respondes. 

[FoxSquirrel]

Try just selecting "Use Type from NI_VISATypes.ini" and hitting OK.

[panzer099]

Hello All,

        I have encountered same issue about VISA steps.

        1. If I select "Use currently loaded type", I can log in teststand.But the teststand will be crash when I insert a VISA OPEN step and click the button "Configure

VISA open"

        2.If I select second one "Use type from install_NI_VISA types.ini", The error massage will pop up.

Can you please give me some suggestion about that?

    teststand version is 2013.OS is Windows 7.

Thanks a lot.

[Devteck1]

I get the same issue of the visa step locking up Teststand. I have been trying to figure out what the problem is to no avail. So any help with this would be much apreciated. Thanks.

[Daniel-E]

Hello all,

I've been investigating this a bit to figure out what could be happening. I haven't completely figured out the root cause, but I did find a report in our system suggesting that the example can hang for newer versions of VISA. The workaround we have for that issue is to disable the VISA PXI passport as follows:

1) Open NI Measurement & Automation Explorer

2) Go to Tools > NI-VISA > VISA Options

3) Click on the Passports section on the left side under General Settings

4) Uncheck NiViPxi.dll - NI-VISA Passport for PXI

This seems to resolve the hanging issue. I'm still looking into it to figure out why the issue is happening, but let me know if this works for you or if you still encounter issues after trying it.

As far as the type conflict you saw when originally opening the file, I would recommend choosing to use the current type (the newer version). The CommonResults container shouldn't have changed, but it is better to use a newer version of the type where possible. After choosing this option, you will likely be asked to save the type palette with these changes. After that, you should not see the type conflict dialog again.

[Devteck1]

Ok just to clarify I'm trying to create a sequence that gives me all the functions of a RS-232 port i.e.. config, open, close, read and  write. Now if there is a simpler way to do this by calling some build in API functions please enlighten me. If not I tried using the steps you give me but when I try to open the port I get an error still see attached picture. Ignore the first tree line I was just experimenting with things and they are skipped.

[Daniel-E]

Hey Devteck1,

The typical way to implement these operations in TestStand would be to write code modules to perform these operations. The code could be in a language of your choosing, such as LabVIEW, C, or .NET. The code modules could be very simple wrappers of the VISA functions or more complex code to abstract away the low-level settings of the port--the choice is up to you.

The example you found implements this as a C DLL with custom step types to encapsulate the functionality. The challenge with this approach currently is that the example was written quite some time ago (2007) and best practices have changed a bit in terms of how data is passed into the DLL and how C DLLs should interact with VISA. One advantage to writing the code modules in a language of your choosing is that it is easier for you to understand the code and debug it if necessary.

I did try it on my machine, and I was able to do a VISA Open, write data to the port, and then close the port. If you're seeing an error on the Open, it's quite possible that you are providing a resource name (COM port name) which is not recognized. I would recommend opening NI MAX and confirming that you can communicate with the serial port using VISA Test Panels. Once that operation is working properly, the VISA steps should function correctly.