5112 can't be seen after hours of operation

[DMTquest]

After some time (it may be hours or days), my NI 5112 suddenly disappears to my computer. Known of the NI utilities or programs sees the boards at either. I have 5 of these boards in 5 of the same computers and it has been repeated in all. I tested the boards in other computers and they work. Reinstallation, register wiping, and reseating doesn't help my problem. I have latest drivers and am running 2000. I am using DC power to run my computer and am NOT current limited. Early on I did find that large caps were needed on the DC convertors when the computers were run on DC power -- otherwise the PC's would continue to reboot. That problem is fixed, as I said, so we don't think that's an issue. Any ideas?

[Annette Perez]

Hello,

I have only heard of a similar problem when customers used PCMCIA boards and put their laptops to sleep. After recovering, the boards no longer showed up neither in Devices and Interfaces nor in Device Manager. This was a known issue from a particular OS that they were using. Later on, the company for that OS provided a fix for it.

In this particular case it seems that more than a driver or board's problem it is something related to those computers. Probably a problem with the PCI slot, or with the system's power. I came to this conclusion because you have tested all the boards in other computers (different brand) and they work correctly.

Have you tried contacting the computer's manufacturer? Chances are that someone else reported this same
failure. I'm sorry I cannot provide more help...

Annette Perez


Up to what I

[DMTquest]

Thanks for you inputs. I believe you may be correct. After our email, we measured the power supplies and found a drop on the +5 Volt brick. It was low on all computers. We are going to put a capacitor across the output leads to see if that brings it up to the necessary value. The 5 volt supplies are not current limited, but seem to running at voltages from 4.6 to 4.9 volts. They all drop an extra tenth of a volt over time as the systems heat up. Does anyone know what the tolerance of the boards are to voltage? It does not state this information in the manual.

Eddie Hughes