Question USB-HUB disconnection problem

[Kunder_123]

Hi ,

The USB-HUB is self-powered, and two LTE modules are connected via USB-SERIAL to USB-HUB.
We are facing a problem is that,The devices which are connected to USB-HUB can not be accessed. Is there any investigation method and solution for this? please help me out

Below following are kernel Logs.

Kerenl log:
19:47:58 raspberrypi kernel: [ 9301.001438] usb usb1-port1: disabled by hub (EMI?), re-enabling...
19:47:58 raspberrypi kernel: [ 9301.001457] usb 1-1: USB disconnect, device number 11
19:47:58 raspberrypi kernel: [ 9301.001463] usb 1-1.1: USB disconnect, device number 12
19:47:58 raspberrypi kernel: [ 9301.001668] ftdi_sio ttyUSB2: error from flowcontrol urb
19:47:58 raspberrypi kernel: [ 9301.001872] ftdi_sio ttyUSB2: FTDI USB Serial Device converter now disconnected from ttyUSB2
19:47:58 raspberrypi kernel: [ 9301.001906] ftdi_sio 1-1.1:1.0: device disconnected
19:47:58 raspberrypi kernel: [ 9301.002107] ftdi_sio ttyUSB3: error from flowcontrol urb
19:47:58 raspberrypi kernel: [ 9301.003371] ftdi_sio ttyUSB3: FTDI USB Serial Device converter now disconnected from ttyUSB3
19:47:58 raspberrypi kernel: [ 9301.003429] ftdi_sio 1-1.1:1.1: device disconnected
19:47:58 raspberrypi kernel: [ 9301.010150] ftdi_sio ttyUSB4: FTDI USB Serial Device converter now disconnected from ttyUSB4
19:47:58 raspberrypi kernel: [ 9301.010212] ftdi_sio 1-1.1:1.2: device disconnected
19:47:58 raspberrypi kernel: [ 9301.010430] ftdi_sio ttyUSB5: error from flowcontrol urb
19:47:58 raspberrypi kernel: [ 9301.018012] ftdi_sio ttyUSB5: FTDI USB Serial Device converter now disconnected from ttyUSB5


I will appreciate your help and time

 

[Phillip Corcoran]

Log shows multiple instances of "device disconnected" and this is often due to insufficient power from USB ports on bus powered hubs.
A mains-powered USB hub should fix that.

 

[Kunder_123]

Thank you so much for your reply .

Today we tried with single port but we faced the same problem like below.
19:47:58 raspberrypi kernel: [ 9301.001438] usb usb1-port1: disabled by hub (EMI?), re-enabling...

So the error "Disabled by hub (EMI?)" is the impact of Noise or Static electricity?
Can you please tell me. I am awaiting for your answer.

 

[Alabalcho]

As @Phillip Corcoran suggested: Try powered USB hub (hub with stand-alone power supply). This way your RPi won't provide power to the hub, and devices connected to it.
https://www.amazon.com/s?k=powered+usb+hub

 

[Kunder_123]

Thank you so much for your valuable information and your time.

The total current consumption of our LTE module is estimated as 2A.

The USB-HUB is 5V and it has a 3.5A Capability. In addition, CM3 also makes the power supply with this 5V.
So Do we need to separate the USB hub and CM3's power supply?

our steps are like below

1. We are evaluating using CM3.
2. USB hub and USB-UART are boarded on the IO board.
3. USB hub is working in Self-power mode.
4. VBUS-detect of USB-hub uses the same 3.3V power supply as CM3.
5. Set correctly when in Power-On.

and this error occur only sometimes not always.

 

[Kunder_123]

HI,

Please help me out

 

[Alabalcho]

Please help me out

You did not provide any additional information in order to be helped out. Draw a diagram with all the components involved, and connections between them.

 

[Kunder_123]

This is the block diagram. I hope you ll get more clear picture about the problem.

 

[Alabalcho]

Whaw… that's a complex system.. You have to find out whether thesedevices draw their power from the RPi, or from additional PSU.

Get a USB Power Monitor - a device which will let you measure the current an USB device draws from an USB port.