Not Working Maplin A08CQ Revision

[costastep]

this report is in relation to the following one:

#39

and it seems "Compatible USB hubs" table needs to be updated accordingly. so, i have A08CQ unit, but with (Vendor:Product = 0409:005a) and it doesn't support PPPS.

the only visual difference that I can see compared to the Working unit is the color of the Plastic used inside the 2 USB ports on the Front panel (see the picture found in #39 ):

• on the Working unit those USB ports are with Red Plastic
• on my Not Working unit those same USB ports are with White Plastic

of course, I cannot be sure that definitive determines if the unit is working or not, but in any case, not all A08CQ units support PPPS and are compatible with 'uhubctl'.

[SlySven]

As the original reporter - who still has the unit somewhere - I'd admit I am surprised by your (unfortunate) discovery. TBH Maplin back in the day would, I believe, have requested the "proper" PPS functionality from things they sold - of course it is all a bit academic since their economic demise some years back. I will dig my unit and confirm that it does still behave correctly with the current uhubctl software.

Do the port specific LEDs change state at all when you send the appropriate uhubctrl commands? Have you connected the external supply which you will need if using devices that do draw the 500mA maximum that a USB2.0 port can supply - I would expect the LEDs to reflect the power state but I haven't tried to see what happens if I try to overload things by powering it (and down stream devices) from the upstream port only and selected more than one device (such that together they and the Hub would exceed the 500mA from upstream)?

[costastep]

@SlySven : thank you for making the initial report - that's what made me try the device in the first place. so, on your questions/suggestions:

• the "Power" Indicator of (my) A08CQ has 3 states:
  1: Red: external Power Adapter is connected (5V, 3.5A, i.e. 7x ports 500mA each)
  2: Green: external Power is not connected, but the hub is connected to USB Host port (of device like PC) and getting its power from that USB Host port, i.e. limited to 500mA in total
  3: (Red + Green): external Power Adapter is connected and the power is taken from there, USB cable is connected to USB Host port (of device like PC), but it's used for Data only

so, I tested in case 3, but next point explains why I doubt that really matters.

• my A08CQ reports no PPPS support:

Hub Descriptor:
  bLength               9
  bDescriptorType      41
  nNbrPorts             4
  wHubCharacteristic 0x00a0
    Ganged power switching
    Ganged overcurrent protection
    TT think time 16 FS bits
    Port indicators

instead it says "Ganged power", which according to the FAQ section here, means that "all ports at once" are powered with no ability for individual switching of each port power.

• further more my A08CQ is made of 2x 4-port chips ("NEC 720114") so to say "daisy-chained" together to make 7-port hub. essentially, the 2nd 4-port chip is connected to one of the ports on the 1st chip, very obvious from the 'uhubctl' output:

Current status for hub 3-4.4 [0409:005a, USB 2.00, 4 ports, ganged]
  Port 1: 0100 power
  Port 2: 0100 power
  Port 3: 0100 power
  Port 4: 0100 power
Current status for hub 3-4 [0409:005a, USB 2.00, 4 ports, ganged]
  Port 1: 0100 power
  Port 2: 0100 power
  Port 3: 0100 power
  Port 4: 0507 power highspeed suspend enable connect [0409:005a, USB 2.00, 4 ports, ganged]

• I used "-f" option and forced with 'uhubctl' all those ports to off:

Current status for hub 3-4.4 [0409:005a, USB 2.00, 4 ports, ganged]
  Port 1: 0000 off
  Port 2: 0000 off
  Port 3: 0000 off
  Port 4: 0000 off
Current status for hub 3-4 [0409:005a, USB 2.00, 4 ports, ganged]
  Port 1: 0000 off
  Port 2: 0000 off
  Port 3: 0000 off
  Port 4: 0507 power highspeed suspend enable connect [0409:005a, USB 2.00, 4 ports, ganged]

but after checking with multi-meter/voltmeter all 7-ports are still outputting 5V. so, there is no any doubt my A08CQ hardware revision cannot shutdown the power.

[mvp]

Added a warning note to README pointing to this report. Thank you @costastep!