Cannot initialize the HP6810A power supply

[Kaspar]

Hello,

   Does anyone have a idea over why randomly get the following error message from the init vi for the HP6810A power supply?

Error -1223 occurred at HP68xxA Initialize

Possible reason(s):

LabVIEW:  Instrument identification query failed.

I have verified that the VISA resource name is correct.

Regards,

Kaspar

[Dennis_Knutson]

The first thing to check is to place a probe on the VISA Read to see what is actually being returned. If it fails with something completely different than the normal *iDN string, then it's possible that the write buffer of the instrument still has the result or a partial result from a previous query. For example, if there are hundred bytes in the buffer and a read requests 90, then the next time you do a read, you will get the remaining 10 bytes. In some cases, before that happens, the instrument will throw a query interupted error but I'm not sure about this particular instrument. If you do have results from an earlier query remaining, you can try to find where that might be happening or at the beginning of the program, do a read and discard any data or any read timeout error you get.

[Kaspar]

Hello,

  I have added a VISA read (with 200 bytes) prior to when I try to initialize it, and I am still getting the same error. Any other ideas on what is going on?

Regards,

Kaspar 

[ceties]

Have you tried turn it ON and OFF? (IT CROWD) 🙂

Now seriously. I haven't found any details abou your device. How do you connect it? I assume over serial port so have you set properly parity and so on? Also the termination char may be an issue. If you connect it via GPIB is the address correct? I would also suggest you to start with the examples shipped with LabVIEW e.g. 'Basic Serial Read and Write'

Message Edited by ceties on 05-21-2008 01:01 PM

[Kaspar]

Helllo,

  Yes, I have done the obvious, turn it off, wait 30 seconds, turn it on and wait 30 seconds, at least until the POST is complete! I hope that "THE CROWD" appreciates the humor, at least I did. Right now I am seriously contemplating chaing the power supply to my car bumper and doing donuts in the parking lot if I cannot get this resolved before I go home today.

   Adding the VISA read has not corrected the init problem.  How do I ignore the read error? The error out is not connected to anything, but yet I still see a error dialog .Any other ideas?

Regards Kaspar

[Matthew_Kelton]

When the error occurs, have you looked at the expected and receievd string to determine why they are not the same?  Is this a driver you have written, or are you using a device driver someone else has written?

[Dennis_Knutson]

Did you actually look at the data being read? Did you actually compare the return string with what is expected? Would it be to much to ask you to share that information? At this point, it's impossible for someone to say whether the instrument or the driver has a problem.

As far as ignoring the error, it would seem that you have automatic error handling turned on.

[Kaspar]

Hello,

   I am just trying to do something very simple, initialize the HP6812A with a vi named HP68xxA. I am not sure where it came from, I am assuming from NI and/or HP/agilent, Because I am trying to initialize, ther are no input strings or output strings. The inputs are error in and the instrument descriptor, bot of which I have verified to be correct.  I have looked at the block diagrams of the drivers and I have noticed that the VISA open vi's are called Old Visa Open. So this my be a clue and I should probably try to update the VISA opens to a current VISA open and see what happens.

Regards,

Kaspar

[ajckson]

One of the first things that I try with GPIB to make sure that I can communicate to the device is the *IDN? command.  Have you used the GPIB read write in the example finder?

Make sure that you know the GPIB address of the HP6810A first, the HP's usually flash it on power up.  Set the address in the vi to that and send the *IDN? command, do you see anything?

Is there another GPIB device on the bus with the same address?

[Dennis_Knutson]

Of course there are input and output strings assuming you are using a LabVIEW driver and not a CVI/IVI driver. Since you see an old VISA Write, it's bobviously a LabVIEW driver and there is a VISA Write and A VISA Read. The VISA Read returns the results of the VISA Write that is sending a *IDN? string. Probe the output of the VISA Read. What ii is being compared to is right on the block diagram as well. And yes, the old VISA Write should be replaced.