My question is around Max Power on USB ports communicated by the OS. A standard Computer USB should be able to provide a Max Power of 500mA. I ask as I have a Nuance PowerMic II and III that when I run CMD lsusb -v|egrep “^Bus|MaxPower” I get the following,
lsusb -v|egrep “^Bus|MaxPower”
Bus 002 Device 007: ID 1b1c:1b09 Corsair Vengeance K70R keyboard
MaxPower 500mA
Bus 002 Device 005: ID 046d:c063 Logitech, Inc. DELL Laser Mouse
MaxPower 98mA
Bus 002 Device 004: ID 0c27:3bfa RFIDeas, Inc pcProx Card Reader
MaxPower 100mA
Bus 002 Device 006: ID 0554:1001 Dictaphone Corp.
MaxPower 100mA
Bus 002 Device 003: ID 0451:2036 Texas Instruments, Inc. TUSB2036 Hub
MaxPower 100mA
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
MaxPower 0mA
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MaxPower 0mA
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
MaxPower 0mA
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MaxPower 0mA
So Question is Why does Keyboard show correct Max 500mA and the Dictaphone Corp Device show a MaxPower of 100mA. Reason I ask is that Nuance states the PowerMic requires 500mA’s to work correctly. I have looked Everyone I have asked states that there are no setting in IGEL to manage or set the Max Power so where does it come from? We are having issues in Dragon with PowerMic’s in VMWare sessions where they are being dropped by Dragon but the device is still attached to the session and they are trying to say it is a problem with IGEL as they do not see the issue on widows? any help or information would be appreciated.
USB provides at least 100mA power according to the USB standards. If a device needs more power it can request this. For USB 2.0 the maximum is 500mA, later USB versions can request more. If you use a bus powered USB 2.0 hub it can provide only 100mA (max. 4 Ports and 100mA will give you the maximum of 500mA again). If you want do connect devices that need more you will need a self powered USB hub that comes with its own power supply. If the PowerMic is connected to a passive USB hub without its own power supply it will only get 100mA from the hub.
If you plug it into the endpoint, you should be on the save side power consumption-wise. The 100mA you read are the values the device claims to need in general. Not the milli amps it can get from the actual USB socket it is plugged into.
I’m not an expert here but to my knowledge, the socket isn’t constrained to the 100mA if it’s still in the range the socket can deliver.
I think it’s more likely to fail on how exaclty the device is redirected. Dragons be here.
Thanks for the info, That is what I assumed as well but they have come back a few times and say that because I provided that info that it may be the reason why it is having issues. I have a USB Power meter device, I will test it with the Mic to see if it pull more power etc next time I am on site with a Mic. I have implemented there suggested Redirection settings and it made no difference. It appears to be a problem Dragon Software and the custom integration into one of our Cerner Products and just started being a major problem after a update a couple of months ago. I will do the test so I can shut them up on that one tomorrow. Thanks again
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