NI GPIB-USB-HS - Issues - Page 1
Forum section: electronics / testgear

author: ordnit
author_rank: Newbie
timestamp: August 05, 2021, 06:10:05 am
content: Hi there,as you can see from the subject, I'm struggling with this interface. On May 2020, as I was studying Labview, I managed to use the interface with an Agilent multimeter to perform some easy monitoring tasks. After one year, I connected the interface to the instrument but was unable to access it.NI MAX shows the interface correctly and self test is performed without any issue. As I "scan for instruments" I get a "No instruments were found during the instrument scan". Same problems I have if I connect the interface to an Agilent counter.May be the interface that "has died" on the GPIB side?NI I/O trace screenshot is attached.Thank you in advance for your help.Best regards.

author: picburner
author_rank: Frequent Contributor
timestamp: August 05, 2021, 10:03:13 am
content: Yes, you may have some gpib side problems.Has the NI interface always worked well before?Have you tried to change the gpib cable?Do you have another Instrument to try?

author: rfclown
author_rank: Frequent Contributor
timestamp: August 05, 2021, 08:53:04 pm
content: I second the suggestions of trying a different cable and instrument. I have used GPIB-USB-HS for many years (I have a few) with no issues. I've used them with LabVIEW and other software. I find that they "just work". I've given up on using HP and other brands of USB-GPIB devices. Way too many problems getting them working. I have often found that the scan doesn't find everything. But if things are connected properly and the unit is working it will respond. Most new instruments respond to *IDN?. If things aren't working at all I usually try a different cable or instrument to perform a sanity check. If you don't have another cable or instrument, that suggestion doesn't help much. With LabVIEW, I have had cases where things stopped working and I had to quit LabVIEW and restart it to make it work again (more often with Ethernet connections than GPIB).If LabVIEW isn't working right, I'll try it with a C program which uses NI VISA (the same thing LabVIEW uses). I've attached the c program I use. I compile with gcc. To compile in a command window (PC) I type:gcc visa.c -l:"C:\Program Files (x86)\IVI Foundation\VISA\WinNT\lib\msc\visa32.lib" -o visathis assumes the default directory for the 32 bit VISA install on a Windows machine. I've also attached a visa_find program. The exe.zip contains compiled versions from my 64 bit Win10 machine. You'll have to recompile to run on Win32bit. I use the CodeBlocks install to get gcc, but don't use the Codeblocks IDE; I just compile from the command line.

author: ordnit
author_rank: Newbie
timestamp: August 06, 2021, 10:50:11 am
content: Thank you all for support and help.This morning I made a test with another instrument: I have two 34401A "the twins". The first one was not working and not recognized by NI MAX. The one I testedthis morning worked like a charm. It was detected by the software. I could not test it in deep as I had to face a black-out at workplace but this means that theinterface is working. As soon as I come back from holidays, I'll try to resolve the issue I have with the other twin and with the counter 53131A which is the device I need to control.Thank you for software, I'll give it a try.Best regards.

author: ordnit
author_rank: Newbie
timestamp: September 08, 2021, 01:08:58 pm
content: Hi there,long story short: it was my mistake.When I attached the NI adapter to the counter, I notice it was somewhat "loose". So I tighten the screws and made my software tests. No good. Being quite out of ideas, I took an old and dusty GPIB cable and connected the adapter to the female cable connector. Automagically, the counter was clearly visible on labview and I was able to get data from it. So it was a mechanical problem: the GPIB interface is too thick to mate with the counter. A lot of time lost, a new lesson learned: problems are not only in software, debug them starting from physical layer!Thank you for your help.Best regards!