USB, Windows 10, eLink, Elite and Power Management through USB Root Hubs

[Augustus Caesar]

Just an observation when attempting to fix a USB issue for a client today.

 

The problem was virtually every time she plugged in a printer (it could not be networked) to a user's PC or laptop at work it would sometimes do its job and other times it would not. She made a point of asking the relevant users to plug the USB cable into the SAME socket as they have always done.

 

Until recently it worked 90% of the time apparently (I cannot verify that though for obvious reasons) now they struggle to get it to work. On the verge of buying a new printer she spoke to myself who agreed to go to her 'palace of an office' to take a look at the issue.

 

After many attempts I couldn't get the printer to work much more than 50% of the time after connecting and reconnecting the machine to each PC or laptop.

 

Now, what does that have to do with model railways and DCC?

 

Here's the rub... after being there for about an hour or so I decided to check power management for each USB Root Hub in Device Manager. This is not something one would normally check though but I decided to do it. Within each USB Root Hub setting I disabled the option for 'Allow the computer to turn off this device to save power'. When reconnecting the printer it worked every time on each machine but I had to restart each machine for the option to become fully deactivated.

 

So, the upshot is that power amangement in the root hub can and does affect USB sockets and whether or not they can deliver power or even be picked up by the system. Normally each time a device is connected the socket should automatically detect it... however, some are NOT. This could be one of the reasons why.

 

So, if you have errors when connecting the Elite or eLink units and Windows does not pick up the device straight away when drivers are installed then disabling the power management may help.

 

For example:

1. Open Device Manager in the Control Panel (you can do this several ways)
2. Scroll down (if you need to) to the bottom the list where you will see 'Universal Serial Bus Controllers'
3. Expand the same by clicking its little arrow to the left of the item
4. Double click each USB Root Hub item (one at a time of course)
5. Click the Power Management tab and remove the tick from 'Allow the computer to turn off this device to save power'
6. Click OK and close all open windows
7. Restart the laptop or PC (important you do this)

 

Now try attempting to reconnect the Elite or eLink (or whatever other device is giving issues) to the USB socket of your choice (making sure the Com port used is BELOW 5).

 

Hope this may be of help to some users.

[choralc]

AC would this be with Windows 10 or any PC OS?

[Augustus Caesar]

Choralc...

 

Good question. I did the original fix in Windows 10 and hurriedly put this post up before I forgot about it with it being relevant.

However, the same would go with all versions of Windows where Power Management is associated with the USB Root Hub properties in Device Manager.

This means XP, Vista, 7, 8, 8.1 and 10. Also server versions of Windows. All accessed exactly the same way as described in the 7 points in my orginal post.

[96RAF]

Very informative AC especially as yesterday I spent hours trying to get my Airprint printer to work. It was getting to the point of a drop test - i.e. into the bin.

 

It was OK with the main PC on USB but could not be seen by either our phones or iPads wirelessly, which as usual had been working fine with the printer for ages.

 

Last night I switched everything off at the wall including the router and bingo at cold reboot this morning everything works again.

 

I will however do the windows is helping you save  power check that you suggest to make sure it cant help me in future.

Rob