LINDY Technical Support Forum

I have a Lindy USB 1.1 4 port extender connected together with 15 meters of Cat5e - the hub is self powered.

Connected to the hub are 3 devices and a self powered 4 port hub with another 4 devices connected.

Everything works great for a while - anything from a few hours to a day passes and then the extender hub and everything attached to it vanishes from the USB bus.

I have all power saving for the USB hubs deactivated.

I have tried to implement a kind of stay alive by sending data to one of the usb devices every 5 minuets but it has no effect.

I have tried installing an after market PCI USB card and connecting the extender to this with the same result.

I have tried installing a second extender and only having 4 devices on one and 3 on another - same result - the hubs randomly drop off the bus.

After around 10 or 20 mins the hubs often re-appear on the bus again.

I have written a piece of code which queries the Win32_PnPEntity for USB devices and counts them so I can monitor when the hubs vanish and there seems to be no particular patten to it.

All of the USB devices (4 virtual com ports, 2 LibUSB devices and 1 HID device) are using the latest drivers.

I am running Windows XP with all the latest updates.

Any advice on where to turn next?

Mike

Hello,

Was the second extender installed on the same PC / location?

I would be very tricky to troubleshoot such a setup as it could be caused by quite a few things. Is it going near any high voltage power, lighting or anything that could effect the signal? (Microwave nearby?)

We have sold hundreds of these over the last 6 years and I've not seen this happen before in our testing.

Chris

Was the second extender installed on the same PC / location?

Yes the second extender was connected to the same PC

I would be very tricky to troubleshoot such a setup as it could be caused by quite a few things. Is it going near any high voltage power, lighting or anything that could effect the signal? (Microwave nearby?)

No microwave on site but the cat5 cable does pass twice over power cables for florescent lighting.

The building is not used most of the day and all power is off - I have checked the door access logs and there are people at the club when the hubs drop off the bus so I guess this could be the problem.

Bypassing any contact with power cables could be done but would mean extending the cable run to around 30 or 40m - would this be ok...what is the maximum run length suggested?

Mike

Hi Mike,

On these we recommend below 50m, but it depends on cable quality.

If possible it would be good to test the current whole setup on a bench away from the mains. This should give you a good idea.

Florescent lights do pull a lot of power when starting and also the starters are very noisy.

Chris