USB OverCurrent Notice????
- Thread starter dixonbm
- Start date
DeltaMac
Tech
USB can be connected in 2 ways: self powered (through the USB connection), or externally powered through an external power connector (usually a wall wart of some kind). You probably exceeded the total current available through your hub. This can usually be avoided by using the external power adapter connected to the hub (some hubs are not sold with power adapters, USB bus power (or self-powered) often is just fine). If you already have your hub externally powered, you may need to go to a newer design hub, such as those advertised to support USB 2.0, or USB Hi-Speed, should better support the requirements. Also, 7-port USB hubs can supply more power to the ports, and may give you more 'room' for other devices.
USB standards allow for up to 127 (!) devices, that's a lot of hubs! (Just imagine the lineup of wall warts for that!)
USB standards allow for up to 127 (!) devices, that's a lot of hubs! (Just imagine the lineup of wall warts for that!)
DeltaMac
Tech
If you go to Apple Sytem Profiler, click on the Devices and Volumes tab, and click around to the various USB items, you'll what the individual devices say for current draw.
Apple says each bus can have up to 500 ma power through each USB port without a powered hub.
Is your hub attached to the keyboard port, or directly to the USB port on the system.
Is your 2nd keyboard plugged into the 1st keyboard?
Double check your external power for the hub, sometimes a power supply dies (or accidentally dis-connected), and on USB you may not notice until too much power is drawn. If you unplug and replug the hub's power supply, most hubs lights will change as a result, that will tell you the power supply is working.
Or, you may just simply have a poor quality USB hub.
Apple says each bus can have up to 500 ma power through each USB port without a powered hub.
Is your hub attached to the keyboard port, or directly to the USB port on the system.
Is your 2nd keyboard plugged into the 1st keyboard?
Double check your external power for the hub, sometimes a power supply dies (or accidentally dis-connected), and on USB you may not notice until too much power is drawn. If you unplug and replug the hub's power supply, most hubs lights will change as a result, that will tell you the power supply is working.
Or, you may just simply have a poor quality USB hub.
DeltaMac
Tech
You didn't post all the info, which of these devices are full power, or low power? (you can view that in Apple System Profiler (Devices and Volumes tab). I would be most concerned about the IR adapter, and the APC (aside: does the control software for that APC work OK for you?)
Just curious: what brand of USB hub are you currently using?
I used to have a belkin, that occasionally gave me over-current with 2 printers and a scanner, changed to a D-link a few months ago. Now it's smooth-no USB warnings-no other changes except the hub.
YMMV, I'm just reporting what I've seen.
Just curious: what brand of USB hub are you currently using?
I used to have a belkin, that occasionally gave me over-current with 2 printers and a scanner, changed to a D-link a few months ago. Now it's smooth-no USB warnings-no other changes except the hub.
YMMV, I'm just reporting what I've seen.
Sorry for not including everything before.
By the way Since rearranging the way I had them plugged in I haven't gotten the warning any more. Only thing that changed was order on the hub.
Do you know what the difference between the speed full and low are? Also could you explain a bit more how the power thing works.
Thanks.
computer:
keyboard 1 - Full - 500
powered hub - Full - 500
powered hub: (Hub is a belkin & the power is plugged solidly into APC)
bluetooth - Full - 500
keyboard 2 - (Says hub first - Full - 500 and then keyboard - Full - 250)
Epson Printer - Full - 500
APC Battery Backup system - Low - 100
Keyboard 1:
Kensington mouse - Low - 100
Keyspan IR adapter - Full 100
I haven't actually tested out the APC software yet. I have been meaning too though.
By the way Since rearranging the way I had them plugged in I haven't gotten the warning any more. Only thing that changed was order on the hub.
Do you know what the difference between the speed full and low are? Also could you explain a bit more how the power thing works.
Thanks.
computer:
keyboard 1 - Full - 500
powered hub - Full - 500
powered hub: (Hub is a belkin & the power is plugged solidly into APC)
bluetooth - Full - 500
keyboard 2 - (Says hub first - Full - 500 and then keyboard - Full - 250)
Epson Printer - Full - 500
APC Battery Backup system - Low - 100
Keyboard 1:
Kensington mouse - Low - 100
Keyspan IR adapter - Full 100
I haven't actually tested out the APC software yet. I have been meaning too though.
DeltaMac
Tech
Sounds like you have it sorted out. I was going to suggest moving devices around on the hub (like connector 1 should be the highest power, or maybe #4) The Bluetooth puts you on the edge, I think. You may be able to see the message again by unplugging the Bluetooth, and re-inserting, but why?
Consider a future hub puchase, either to piggy-back on this one, or replace with a 7-port. As you can see, you're maxed out now. The IR adapter maybe should also be on a powered hub, too. Just something to put on a list of things to do.....
Consider a future hub puchase, either to piggy-back on this one, or replace with a 7-port. As you can see, you're maxed out now. The IR adapter maybe should also be on a powered hub, too. Just something to put on a list of things to do.....
DeltaMac
Tech
Just a suggestion, a device that essentially provides a networking connection (IR) may work more reliably on a self-powered bus. Not a requirement, but just a hunch from past troubleshooting. It's probably OK where you have it, it is a low-power device, but full speed. I wouldn't make a special trip to add a hub just for that one device, just if you do, it would be one device to consider on a hub if you have the space.