Prologix LabVIEW write/read error

[AM33]

Hello,

I am a student/research assistant working on a LabVIEW program that was passed on to me from another student. I am not sure what happened between taht time and now but I am having problems with a write/read step from a Prologix GPIB. I have attached the vi code as well as several screen shots. I have checked the read/write module without running the program and I get a green arrow but still get a error code. After running the program, I get an error that is visible in the block diagram. I am really not sure what to do about this. By the way, I am taking measurements from a Homodyne setup. I will appreciate any help or suggestions. Thank you for your time.  

[AM33]

I wanted to add more attachments

[AM33]

Still more attachments

[AM33]

One more set of attachments after this

[AM33]

Last attachment

[Daniel-E]

Hey AM33,

I can think of a few things we could check here. First, this error can be caused if you are trying to access the wrong VISA resource. Can you verify that the VISA resource name you have selected is correct? Since computers often have multiple COM ports, it's easy to pick the wrong one on accident.

Second, which version of the NI-VISA driver do you have installed on the machine? You can find that by going to the Measurement and Automation Explorer (Start > Programs > National Instruments > MAX) and find it under the Software tab. The latest version of VISA is 5.3, so if you don't have that version, I would recommend downloading it. You can find it here: http://joule.ni.com/nidu/cds/view/p/id/3823/lang/en

Finally, do you have any other code which can successfully communicate with the device? It might be good for us to work off of an example, to narrow down whether this is a problem with the code or with the hardware connection itself. Did the device come with any LabVIEW programming examples, or do you have any existing code that does work with the device?

[AM33]

Thank you. I will try that out today.

[AM33]

Unfotunately it did not work. I unplugged the GPIB from the USB drive and the program worked exactly the same

[Daniel-E]

AM33,

I'm not sure I understand. Rather than unplugging the GPIB device, can we instead make sure we have the correct VISA resource name or COM port for the device, and make sure the LabVIEW application is configured to use that VISA resource?

Also, it you could let us know what version of VISA you're using (steps for that are in my previous post) that would be helpful as well.

Finally, do you have any other software (such as another LabVIEW program, or a program created by the device manufacturer) which is able to communicate with the device?

[AM33]

Hello Daniel-E,

I updated the VISA to version 5.3. I am using LabVIEW 2010. I am using the latest driver for the Prologix GPIB (2013). I checked that I am to use COM port 7. When reopening the program, I change it from COM 4 to COM 7. The program worked about a month ago. I am not sure what I am doing incorrectly. I have checked set-up several times. It seems as though the "write" step is not have usable data. The "write" step times out and gives a "-107..."  error code. I did not find the error code in the zone protion for the website. I am aware that without the negative symbol, the error code would mean an empty register. Thank you for your time in reading this reply.