Ethernet control of Tektronix scope using VISA

[srini]

Hi,
I have got a new scope, TDS7104 and I want to remotely control it through the Ethernet port. Can anyone help me on how to do this using VISA. I haven't used VISA and I don't know how to start. Most of the examples I have seen are for GPIB and serial interface control. So, I am not clear as to how to use the Ethernet port to control the scope. With the scope, there is a TekVISA software but the examples they have given are for command line programming through C and I don't know how to do it in LabVIEW. Any example would be of great help.

Thanx & Regards,
Srini.

[craigherdman]

There is a great Knowledge Base article on our website that discusses how to control Ethernet instruments with NI-VISA found here.

While I am unfamiliar with using Tek-VISA, NI-VISA does have many cool features. Some of these features include the VISA Interactive Control where we can open VISA sessions on the fly without any programming, NI-Spy which allows us to log all NI-VISA driver calls helping us narrow down programming errors and behaviors, and seamless integration with Measurement and Automation Explorer allowing us to configure VISA and test our devices all in one place. More information on NI-VISA can be found at the following document links:

”NI-VISA Product Information”

Hope that helps!

Craig H.
NI Applications Engineering

[Dennis_Knutson]

Just to add to what Craig said, you should go to MAX>Devices and Interfaces, right click and select Create New>VISA TCP/IP Resource. You have to know whether the instrument is VXI-11 or not. If it's not, you have to enter the IP of the instrument. Make sure that the IP of the instrument is set to the same subnet as your network.

[srini]

Hi,
I couldnt get how to goto MAX>Devices & Interfaces. But I tried the following.

I installed the TekVISA in my PC. In LabVIEW tools menu, I selected Instrumentation and then Import CVI driver and selected the tktdsk7k.fp and the corressponding dll file. These files came along with the scope under the name VXIpnp drivers. Then, LabVIEW has made a lot of vi's from these files. I opened a new vi and pulled the intialize.vi and the close .vi to check whether it is communicating with the instrument. In the resource name of the intialize.vi, I gave TCPIP::::INSTR. I am getting the following error. Plz help me.
Error code: -1073807343 Insufficient local info or the device or resource is not present in the system

I dont know whether this is the right method or not bcoz no manual speaks about this and I dont have any examples vi's also. Any example will be of much help.

Thanx & Regard

[Dennis_Knutson]

I can't help you with TekVISA. I've never used it and I don't know what configuration utilities it has. If you had installed NI VISA, then you would have Measurement & Automation Explorer (MAX) on your desktop. As I mentioned in my previous post, MAX with NI VISA will walk you through the setup of a TCP/IP instrument. However, with either NI VISA or TekVISA, TCPIP::::INSTR is an incorrect instrument descriptor. You would need the IP address of the scope in there like TCPIP::192.168.250.100::INSTR. The actual IP address must be set to on be the same subnet as your network. Before you try to communicate with the instrument, make sure that you can ping it first.

[srini]

I tried pinging theinstrument and got a reply. I gave the IP address in the same way as you have told and the instrument has the same subnet as that of the host PC.Anyway I will try to get NI-VISA. Thanx for help. Will contact if further help is required.

Regards,
Srini.

[srini]

Hi,
I was able to communicate with the instrument using TekVISA library in LabVIEW.I initialized the scope and used the getwaveform.vi to acquire the signal and wanted to display it in a graph. But I am getting an error:Invalid data array size.How to avoid this error?

Thanx & Regards,
Srini.

[craigherdman]

srini,

I surmise that you are using the LabVIEW instrument driver wrapper for the C-based instrument driver for your TDS 7104. In that case the error could be thrown by either the LabVIEW wrapper or the actual instrument driver itself. Perhaps you could post a screen shot of the error? If the problem is happening with the LabVIEW wrapper then we can take a look at it otherwise this is likely a TekVISA issue that we do not support.

Craig H.
NI Applications Engineering