Instrument not found

[UKnowWhat]

My GPIB-USB-HS from my laptop could not find my 2 HP-8753Cs (and the Amrel PPS 60-1D Power Supply) and returns the error "Instrument not found". Another USB-HS had the same problem with these instruments. However, other desktops using PCI-GPIBs can communicate fine with the HP-8753C & the Amrel PS (with IDN error of course). These USB-HS are fine when connected to other "old" instruments like HP-8566B, HP-438A (or newer instruments) and I've make sure that none of these instrument occupied address 0. My NI-488.2 driver is 2.5. Any idea of how to fix this problem? I don't have any other brand GPIB-USBs here (all NI brands) to try if indeed it's a compatibility issue.

Thanks
Lanny

[UKnowWhat]

Here is the spy capture

[Chad B]

Lanny,

Hi, this is Chad from National Instruments. When you say you can communicate with them with an IDN error, what exactly do you mean?  Do those instruments respond to a *IDN? request from the PCI-GPIB board? If not, are you interacting with them using a LabVIEW program, or with IBIC commands?

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@UKnowWhat wrote:
However, other desktops using PCI-GPIBs can communicate fine with the HP-8753C & the Amrel PS (with IDN error of course).

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[UKnowWhat]

Hi Chad,

I use NI Meas & Automation Explorer to make sure the instrument can be seen before I attempt to write any program. We all know that old instruments don't repsonse to *IDN? request but at least, they are recognized on the bus. My issue is NI Meas & Automation Explorer using NI GPIB-USB-HS does not recognized some instruments as listed above. I have 2 of them did the same thing and as a result, I've switch to a desktop with a PCI-GPIB . It is very inconvenient to haul in a big desktop and a monitor into a small confined area.

As a matter of fact, I think I have the same problem with a rented Agilent N5230A VNA 5 months ago, but I was pressed for delivery so I switched to a desk top with  PCI-GPIB without looking into it further.

[Can_W]

Hey Lanny,
Sorry to hear you're having all these issues. Since you have been able to see and work with other devices, I don't think that it's a driver issue. And since you've been able to work with them through PCI, it's probably not a compatibilty issue. The problem may be caused by an address conflict. Do you have multiple instruments connected to it at the same time? If so, try changing the address of the other instruments to something really high, like 9, so there are none that have the same.

Hope this helps

[UKnowWhat]

Hi Can,

I did that too. Connect only one instrument and change to different address. Could it be the timing issue that these old instruments need to have a longer time delay between commands? As I recalled, the old Amrel might need 50-60ms delay between comands. The HP-8753C might need a similar delay. Maybe the problem is not with the GPIB_USB but actually lied within your NI Meas & Auto Eplorer. What is the delay between commands of your NI Meas & Auto Explorer? Pretty fast and no more than 10 ms, I suspect.

[Can_W]

Hey Lanny,
I'm a bit confused as to what's happening here now, so if you could please clarify something for me. Is the issue that you cannot communicate with the "old" instruments or that you cannot detect them in MAX?
Also, if you're worried about the timing and delay issues, you can try running NI-SPY when doing a scan for instruments. It will slow down the communication, and also give you a basis of when things are called. You should already have this program, as it was installed when you installed other NI software. It's location should be Start->Programs->National Instruments

Hope this helps

[UKnowWhat]

Hi Can,

MAX did not detect the instruments and neither other 3rd party program (Print Capture) I used to capture the instruments' data through GPIB bus. See the spy file attached at the 2nd post. I did not attempt to write my own program using GPIB-USB-HS once the 2 above fails to communicate. I just scrap that GPIB-USB-HS and use the desktop with a PCI-GPIB. I am very sure if your program (MAX) and your device (GPIB-USB-HS) do not detect an instrument (assuming I 've exhausted all the common remedies that anyone who know how to search would find them) then there are only 2 possible answers for this problem:

1) You have a bug within your program (MAX) and/or (GPIB-USB-HS)
2) The instrument itself is not conform to your thinking of how should it commnunicate

Do you have any HP-8753C/D/ES in your lab? Plug in it and tell me the answer, would you?

[Can_W]

I would be hesitant to say that it is an issue with MAX, since you have been able to communicate with your devices via PCI. I'm still looking into the issue, but it really would be helpful if we were able to get results from another party, to clarify if the instruments are the issue. I will do my best to get you a resolution as soon as I can.

Thank you

[UKnowWhat]

Thank you, Can. When (and IF) I finish with the current project, I would attempt to write a simple program to communicate with the HP-8753C using a laptop and GPIB-USB-HS and debug it from there. If I can communicate the instrument then the problem is lying within MAX. If not then GPIB-USB-HS is not compatible to those old instruments. I would let you know the result.