Connecting VXI PC with Sun Workstation

[MF]

Hello,

I am wondering if there is an easier way to connect remotely to a VXI PC and its Instruments than using a VXI TCP server?

Can you connect the VXI PC to Max and have all of the instruments available through VISA?

Where is Max (Measurement and Automation Explorer) on the Sun Workstation? I installed LV 7.1 and did not see any location for this.


These are almost all of the questions, I promise.

Michael Froehlich
Lakewood, CA

[JohnM 64]

Hello MF,

If you are looking to have an embedded controller on your VXI system, then you will see all of the instruments in MAX on the embedded controller. You can open VISA sessions to these devices through MAX. If you then want to get data from that computer to another remote computer, then TCP is a good solution.

If, however, you do not need to have an embedded controller, there may be other ways to accomplish what you are looking for. There are other forms of controllers, including MXI-2 and USB. In this case, the chassis is actually controlled by a separate computer from the VXI chassis. The data passes through the MXI-2 or USB controller to the computer, and all the devices will show up in MAX on that separate computer. This may be more of what you are looking for. However, if you are looking to have a computer a great distance away from the chassis, then this solution may not work, because the distances are limited (about 2 meters in the case of MXI-2).

Currently there is no MAX for the Solaris operating system. That is why it cannot be found on your Sun Workstation. Although there is no MAX, there is a VISA Interactive Control (VISAIC) that can be used to communicate using VISA to your devices.

Hope this helps!

john

[Richard Thrapp]

Hello, Michael and John,

I would like to add some additional information to John's answer.

You can use Remote VISA on your Solaris workstation to access the VXIpc's VXI interface using the same VISA API you would use to access a local device. First, on your VXIpc, you should install VISA Server if it's not already installed. (It likely is already installed, so you can probably skip that step.) Then configure the VISA Server through your VISA options in MAX to start when the computer starts and allow connections from your Sun workstation. After setting up your VXIpc in this way, from your Sun workstation you can connect to any VISA resource on the VXIpc by specifying the resource string "visa://[address-of-VXIpc]/[local-resource-name]". "[address-of-VXIpc]" should be replaced by the IP address in the form "a.b.c.d", or by the VXIpc's network name, and the "[local-resource-name]" should refer to any VISA resource that is on the VXIpc, such as "VXI0::0::INSTR". You can even use viFindRsrc() to find remote resources with this mechanism.

Using this information, you should be able to write your VISA application on your Sun workstation. To test your remote VISA setup, you can run NIvisaic on your Sun workstation to access the VXIpc interactively.

Note that if you are doing a lot of single-point access, with functions such as viIn and viOut, or using other small transfers, these accesses will be considerably slower than they would be if written directly on the VXIpc, as each one must travel across the network to get a response, and networks have a high latency.

Also, you will need NI-VISA 3.1 on your Solaris workstation to access your VXIpc this way.

--
Richard Thrapp
Staff Software Engineer
VXI Software