I will run your Code shortly and let you know the outcome. My current system configuration is as followed: -VISA 3.1, LabVIEW 7.0, OS WinXP(a non-issue I believe). -PCMCIA-GPIB Card 488.2 ver2.1 on the controller side, and HP-IB Bus 488-1975 on the client side (electronic system/coupler). -Yes to both "VISA read execute and take a long time...", and "this is the problem [I am] seeing and that we are trying to solve." Thanks.
Your code and mine appear essentially the same but I like yours because looks cleaner and it's easier to read. After much playing with both and my instruments command sequence and literature research, I am communicating as I expected it with my instrument. Now my next step is to write the driver and from there build the front panel application for my instrument. Thanks for your help.
I do have one last question more about LabVIEW than GPIB though, I need to show on my front panel the data in BIG numbers (perhaps yellow color) on a black brackground. How do you do that? Is using a string control the only way to do this? Thanks.
Glad that I could be of some assistance. The easiest way to display data on the front panel is with a string indicator. You can change the font size and color on it by selecting the box and then clicking on the "font dropdown" at the top of the front panel window. Here you can change the size, color, font, etc. to match what you are describing.
Scott B. Applications Engineer National Instruments
I'm assuming that this error is occurring at your VISA Open, is that correct? This error means that the lower hardware layer did not detect an instrument at the address that you specified. If the instrument is not powered up or has not yet initialized its GPIB communication hardware, this error could occur.
Check your primary address to make sure that it is always being correctly fed into the VISA Open, and also check your cable to make sure that it is good (try swapping to another cable). How long is your GPIB cable? Are there other instruments connected to it? Long cables with multiple instruments (especially if they are not powered on) can cause intermittent prob lems such as this.
Scott B. Applications Engineer National Instruments
I started a service/support call request with Shea. The number is 7046734. He mentioned that he'd discuss it with you if you'd like to take over. I actually prefer phone or email than this forum. In any case I am posting the latest work I've done on the communication portion of my application. I am attaching a word document and latest program (no longer using VISA but rather GPIB functions/cmds) I've written in LaVIEW to communicate with my device. I appreciate your help. I was told my company has already a support contract with NI. Let me know what works for you. Thanks again.
I spoke with Shea and gave him some things to try. Your SR looks fine as far as support contract, so phone support is available to you. I do not do phone support, but will be in contact with Shea until we get this resolved.
Scott B. Applications Engineer National Instruments
Here's my latest attempt (in the form of videos) to developing a driver for my instrument. Hope you can shed some light on this problem. You may need to see them in full view player mode. Thanks.
I wasn't able to tell much from your videos; there didn't seem to be an error that came up. I see that you are running your VI continuously and doing a clear and configure at the beginning each time. I would recommend adding a while loop with a stop button and doing your writes and reads inside that loop with the configure and clear outside at the beginning.
The "no listeners" error may be caused by the program running too quickly for your instrument; try adding a small delay (~10ms) between all of your GPIB VI's. If this fixes your problem, your instrument may be asserting lines that inform the controller that it is ready to receive data before it is actually ready.
Hope this helps.
Scott B. Applications Engineer National Instruments
