GPIB-USB-HS lost connection

[Nick-san]

I have a problem with GPIB-USB-HS on my system. When I ran the application created by myself, I often lost connection to devices. Active LED was blinking to try to communicate to devices but sometimes I lost them but it was not always. Sometimes it works fine. Does anyone have the same or similar experiences with your GPIB-USB-HS?

[r.kenmoku]

Hello Nick-san,

This is Rutsu Kenmoku from National Instruments Japan. 

Are you using many USB devices? If you are, can you please try to isolate the USB device from the other devices (mouse, keyboards...) 

Here is some information on the use of USB use. 

USB Data Acquisition Device Not Responding

http://digital.ni.com/public.nsf/allkb/3EA2432762C45B298625734D0061D527?OpenDocument

I do not know if it is the same for you, but you might loose connection with the USB with a lack of power. 

I hope it is useful information for you.

Rutsu Kenmoku

National Instruments Japan, Application Engineer 

[Nick-san]

I only have one USB device as GPIB-USB-HS but I have 14 GPIB devices connected to it.

I tried to shorten total length of GPIB cable connection but no luck, so I don't think it is power issue.

Because if I had 4-5 devices connected, the same thing happened before when I used the same GPIB-USB-HS.

I will get another one and try it.  It is also suspected to have bad cables. I will keep on investigating.

[Sailing]

Yeah, I have had problems with only 3 devices on it, normally when I parallelize the connection setup. I can get it to work if I serialize the connections. Even the order can matter in a serial setup. Put your most problematic instruments closer to the source. But even with serial connection setup, you will eventually run into a length limit. Not sure if the GPIB-USB-HS can draw enough power to drive a large complex network. You might be better off running your setup with an internal PCI card which might be able to draw more power off the PCI bus.