GPIB NI488.2 problem

[KPRO]

Hi,

I used NI 488.2 and it working well with labview but it won't see any instruments ("There was an error ... when I scan GPIB by NI software) IF THE COMPUTER IS IDEL FOR 30 MINUTES.

I did download and reinstall NI488.2 as per help instruction but the same problem happen. The only way I can make it work is to RESTART my computer. Is there any timeout setting?

It's really frustrated ... Please help.

Thanks

KN  

[crossrulz]

Are you using a USB-GPIB?  If so, there's a Windows device setting to turn off the USB hub after so long of inactivity.  You need to turn this off.

[JÞB]

nice catch Tim!

FAQ 1 : My USB device stops working unexpectedly.

The first thing to look at is the OS power saving options.  There is a global trend towards developing "Green" electronics and energy star ratings are getting fairly common.  "If its not being used shut it off" is nothing new.  Cavemen learned how to bank a fire to preserve energy that would otherwise be wasted.  Likewise, the Windows OS has a power saving feature to shut down power to the USB hubs when no user activity is present.  In Automated systems this feature can cause problems since removing USB hub power will shut down the USB device.   Solution: Use the device manager to change the USB hub Power Options.

In the case that Tim is incorrect in assuming a USB device is the cause we should also point out that Windows power management setting should allways be considered for high reliability systems.  Test and data acquisition systems DO fall into this catagory.  They are performing tasks that are so vital that they can't even be entrusted to humans!

Use the control panel on Windows to keep the machine working even if you need to take a little rest or go to a meeting.

[KPRO]

After changing the power saving option to "Never", the computer was idle for 12 hrs and GPIB still comunicate well.

Thank you very much for your great help.

Khanh

[JÞB]

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@KPRO wrote:

After changing the power saving option to "Never", the computer was idle for 12 hrs and GPIB still comunicate well.

Thank you very much for your great help.

Khanh

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Sounds like a winner then!  Glad to help.  you never know just what hardware the BIOS shuts down and does not come back gracefully