Resource Descriptor for device located in a remote system

[kkwong]

Hi,

I posted this question as a follow up on my previous question.  I think my problem is

What is the "Resource Descriptor" for IVI->logical Name->Driver Session->Hardware Assets, if a the device is located in a remote system?

I read an  article that the resource descriptor "is a string, such as a VISA resource descriptor, that specifies the interface and the address of a hardware asset." The article also has a table showing examples of the descriptors. However, there is another article saying there is a problem for VISA resource descriptor.

So it is a bug in MAX? Any workaround exits? For device in the remote system, I can only see the VISA resource descriptor. There is not NI-DAQmx resource descriptor. Any idea?

Thanks!

[abalma21]

Hi, Andy!

I read your previous question.

Do you actually require to develop your program in C++? I would highly recommend you to use C# or LabWindows/CVI instead as this options are better supported.

I would like to verify some key aspects that could help solve your current question.

You have installed MAX, IVI, NI-SCOPE, and VISA in the XP-PC, am I right?

You said all the devices are connected to the same LAN. Does the PXIe chassis appear in MAX under the Network Devices category?

If you try to configure an IVI Driver Session, does your remote devices appears in the Resource Descriptor from the drop-down list that appears when you double-click its field?

Regards

[kkwong]

Hi gustave21,

C++ is my company test platform so it is not easy to use C# or LabWindodws/CVI.

Here are the answers for your questions

1.  You have installed MAX, IVI, NI-SCOPE, and VISA in the XP-PC, am I right?  Yes.

2.  You said all the devices are connected to the same LAN. Does the PXIe chassis appear in MAX under the Network Devices category? NO. the chassis appears on the Remote System Only.

3.  If you try to configure an IVI Driver Session, does your remote devices appears in the Resource Descriptor from the drop-down list that appears when you double-click its field? NO. The drop-down list does not have the remote device.

Attached please find the screen capture of the MAX in XP.

Thanks!

Regards

Andy

[abalma21]

Hi, Andy!

Your screenshot is quite helpful. It does not look like using an IVI Drivers for a remote connection with a PXI Controller is a proper solution for your initial questions.

As you told on your previous question, you have a computer with WIN XP and PXIe chassis controller PXIe-8135 controller(WIN7) and a PXI-5124 card. The XP-PC and the controller PXIe-8135 are on the same LAN. What you want to do is to use the XP-PC to ask the PXIe-8135 remote controller to capture a waveform with PXI-5124 and send the waveform data back to the XP-PC. In addition, you are developing a C++ program on the XP-PC to accomplish the task.

This is most likely to be achievable through VISA Server or Ethernet/LAN communication

.

How to use VISA Server: https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z0000019LfHSAU

How to get Visual C++ VISA Examples: http://www.ni.com/product-documentation/54549/en/

How to connect Instruments via Ethernet/LAN: http://www.ni.com/getting-started/set-up-hardware/instrument-control/ethernet-connect

As you are working with a PXIe chassis, there should be a more specific and appropriate solution, as for example installing the PXI Platform Services 15.1 on the XP-PC. However, it goes beyond my current expertise.

Download PXI Platform Services 15.1: http://www.ni.com/download/pxi-platform-services-15.1/6032/en/

Regards,

[kkwong]

HI gustave21,

I have already setup VISA server and my XP-PC can connect to the PXI-5124 via VISA.  To my understanding, IVI uses VISA to communicate remote device.  Please correct me if I am wrong.  That's why I am looking to the solution of  My application -> IVI driver  ->VISA->network->PXI-5124.

If I need to use VISA directly,  My solution will be  My application -> My own driver ->VISA->network->PXI-5124.  I have thought about that but I could not find any command that I can use for controlling PXI-5124 visa.  Do you have any reference?

By the way, there is still no answer of  "Resource Descriptor for device located in a remote system" .  Is it a bug of MAX?

Thanks again!

Regards

[abalma21]

Hi Andy,

I do not think it is a MAX bug. Otherwise, I think we are overlooking an important detail.

I kept searching for more info about your current devices and since you have a PXIe-8135 controller connected to your PXIe chassis, I noticed the connection you are looking would be similar to communicating two different computers through Ethernet/LAN, and not the one expected in an IVI or VISA driver.

So, I actually believe that the schematic of the solution you are looking for would be "Application in the XP-PC -> TCP or UDP protocol communication (LAN) -> Application in the PXIe-8135 controller -> PXI-5124 card".

Warm regards!

[kkwong]

Hi gustave21,

Thanks!.  But would that mean all PXI/PCI cards cannot be remotely accessed?  As I know that all PXI cards have to be plugged into a chassis, which should be connected to a PC via control card (in my case PXIe-8135 controller is a standalone computer).  PCI cards have to be plugged into the computer.  

If that is the case, in what situation we can will use VISA and IVI  to control the PXI/PCI cards?

Also, what is the function of "Remote System" in MAX?  

Please advise.

Thanks!

[abalma21]

Hi Andy,

As for what I have searched, PXI systems can be remotely accessed, but they require an Ethernet/LAN connection for this purpose.

Also, VISA and IVI are drivers designed to work with 3rd party instrument control (devices not from National Instruments). NI-DAQmx and PXI Platform Services are the drivers used to control most of NI PXI/PCI cards. However, there are some specific PXI cards that require even more specific drivers, like the PXI-5124 you are using, which is a PXI Oscilloscope that requires the NI-SCOPE driver.

As for what I know, Remote Systems in MAX is used to visualize real-time or standalone systems that are connected to the same LAN as your computer. Usually, PXI chassis are considered under this category.

Regards