keithley 2700 driver problem : VISA Resource not found

[fanbei1993]

  I downloaded the Keithley 27xx driver 2.3 and use USB-GPIB to control the K2700. When I tried to run the Single measurement example, there were many error -410. I tried to add waiting time before sending command to K2700, but the errors still existed.

  The screenshots are attached. Thank you in advance for your help!

[Minions]

Fanbei,

If this instrument is capable of VISA communications through GPIB, then you should be able to run this simple vi and get a response from the instrument.  It is setup to run an Identification query.

[fanbei1993]

Hi Minions,

Thank you. I can run the Simple vi and the identification of Keithley 2700 was returned, so there was no communication error. However, I got error -410 query interrupted when I ran the example Single Measurement in the driver. And I attached the screenshots. Usually this error means the time scales are too small and you need to add waiting time before sending command to the unit. But the error still existed even I add waiting time. Do you have any idea about this error?

Thank you very much!

[Minions]

You can use the simple vi with some slight modifications to replace those supplied driver vi's (Close the connection when the entire task is completed).  I prefer to use SCPI programming rather than those supplied vi's whenever possible.  It provides much better control over setting the instrument up for my needs.  SCPI information is available starting in chapter 10 of the User Manual.  One of the key commands you should consider is the

*OPC?

This will allow the instrument to be configured properly before requesting any responses from it.

CONF:VOLT:DC 10, 0.01, (@101)
*OPC?

Once the instrument responds with a '1' then you can request data with the

FETC?

This query requests that the latest reading be sent back to the user.  It helps to prevent hammering away at the instrument and overwriting its buffers.  Remember, most commands, ranges, resolution, and queries take differing amounts of time to complete their action.  One timing choice will most likely NOT fit all.

[Minions]

Your image shows the error occurring after opening and connecting to the instrument.  This means you are propagating the error into the close vi.  If an error enters that vi, it will by-pass the close command.  This means that it will fail to open another connection to the instrument as it is already open from the first pass.  You should wire the error out of the open vi directly into the input of the close vi then merge the errors after the close vi error out.  If you are running your vi continuously, the open handle will remain open until LabVIEW exits because of the error wiring. 

Opening and closing the connections does consume overhead time that will further reduce your overall loop timing. 

You should always Open once, perform multiple functions, close if opened.  If open failed, allow the error handling within the close vi to naturally by-pass the closing code and exit.

[JÞB]

Let me jump in

Close is Close- close closes regardless of error in.  The session will close.

That driver should not be reporting 3 instances of error -410  There is no error out of Clear data buffer, there is only one query in Configure Measurement.  

How you got a COM4 alias for a GPIB Interface is not understandable.  What are you actually talking to the device through? 

[fanbei1993]

Hi Minions,

Thank you for your information! Actually, I have a code written in SCPI and met another problem "Timeout expired before operation completed", I also posted it. You can look at it if you are interested in that problem.

I didn't run my vi continuously, but the error happened after buffer clear, not after open vi. I think it's the problem about the communication with K2700. Did you met error -410 before? And there are three errors of -410.

[fanbei1993]

Hi Jefff,

Thank you for your reply.

But when I run the program, it also had problem of closing. It didn't close automatically. I use USB-GPIB, and it is shown as a serial port in MAX.

[andmboa7]

Hello fanbei1993

Since this is an error meaning you are not communicating with your device. 

I will try doing the query outside LV. 

Do it on MAX first.

Do you have VISA and 488.2 install on your PC? Have you check compatibility with the versions you have with your OS? Even with the LV version you have?

If you so, did you install it after installing your device driver? This might be an issue.

-Andrea G.

Applications Engineer 

National Instruments

[fanbei1993]

Hi Andrea,

Thanks for your reply!

I installed the NI-VISA driver and NI 488.2 driver. I also check it from MAX, there was no communication problem. But when I ran the example in the driver, there was error -410 and I could not get any data.

Did you have any idea about this?

Attached are the test result in MAX and error when ran the example.

Thank you!

Bei