NI GPIB-USB-HS with VB.NET ( No Listeners on the GPIB )

[Joe_Henderson]

I use the NI GPIB-USB-HS device to communicate with a Fluke45 DMM and it has been working 100% reliably in a VB.NET program until recently. When I issue a GPIB.WRITE command an exception is thrown along with a "No Listener on the GPIB" prompt. I have verified the proper primary address is being used by the GPIB object in the program but as soon as the following statement is executed the exception occurs ...
GpibDevice.Write("VAC")

This serial communications has been working flawlessly for the last 10 years and then it just stopped working. I can still communicate with the Fluke 45 using NI MAX and the VISA debug tool.

Curious to know if anyone has any ideas or has been through this already.
Thanks
George Komisar

[WhiteA]

George,

Could you attach screenshots of the error you are seeing? Also, could you attach screenshots of the code in question. That would be appreciated to get more context on the issue.

[Joe_Henderson]

Hi

The popup message is shown below with the windows form in the background.

The Open GPIB button causes the code shown below to be executed.

While single-stepping the exception is thrown at the first GpibDevice.Write command in the sequence..

MyFluke45.GpibDevice = New Device(CInt(boardIdNumericUpDown.Value), CByte(primaryAddressNumericUpDown.Value), Byte(currentSecondaryAddress))

SetupControlState(True)
GpibDevice.Write("VAC") 'ac volts
GpibDevice.Write("AUTO") 'auto ranging
GpibDevice.Write("RATE M") 'auto ranging

[WhiteA · Accepted solution]

The error : No listeners on the GPIB. occurs when a data-byte operation is attempted with no addressed listeners on the bus. It can also happen if a command-byte operation (ibcmd, SendCmds) is attempted and no devices are present. 

Please see this article describing the error in detail and try the mentioned troubleshooting steps

GPIB Error Codes and Common Solutions: http://www.ni.com/product-documentation/54559/en/#toc3

[Joe_Henderson · Accepted solution]

I haven't had a chance to try all the troubleshooting steps you point to but I am submitting more relevant info

Using the VISA Test Panel in MAX I can get the instrument to respond to the *IDN?\n query (as shown below).

So it appears there isn't a hardware issue.

I am working with Measurement Studio in the Visual Studio environment.

I used a tool called I/O assistant to capture the GPIB bus data which shows the traditional 488.2 calls occuring up to the thrown exception.

The statement ibon(UDO,0) occurs when I close the GPIB channel. And it looks like this ...

Anyway … that's all I've got for now … thanks for your help WhiteA.

[Joe_Henderson · Accepted solution]

The last tool I used was the Interactive Configuration Utility which led to the discovery that the BoardIdNumber portion of the GPIB Address was altered in my GPIB hardware configuration database. Simple code fix. They actually don't mention this in the troubleshooting section, hmmm!  Anyway, the system is rock solid again and thanks again for your help!