SwitchableUSB – 3 Supported Messages
3.10 Reply Device Topology
Sent by a ENCODER device in response to a Request Device Topology message. This message is of
variable length depending on the number of devices that are in the system. The combination of the
information is enough for a client to build and display a device tree.
3.10.1 Field Descriptions
An integer from 0 to 127.
An integer from 1 to 127. If a USB Address is seen which is not listed as
the USB Address Of Parent for any of the devices, then that device is
the root of the device topology.
An integer from 1 to 127. 0 is not a valid number for a port on a hub, so
this field will only be 0 if there is no USB device upstream before the
host.
The USB vendor id from the device descriptor.
The USB product id from the device descriptor.
Byte Offset
+-----------------------------------------+-----------------------------------------+
0 | Magic Number |
+ +
2 | |
+-----------------------------------------+-----------------------------------------+
4 | Message ID |
+ +
6 | |
+-----------------------------------------+-----------------------------------------+
8 | Protocol Version = 3 | Command = 5 |
+--> +-----------------------------------------+-----------------------------------------+
| 10 | USB Address | USB Address Of Parent |
| +-----------------------------------------+-----------------------------------------+
| 12 | Port On Parent | Is Device A Hub |
| +-----------------------------------------+-----------------------------------------+
| | USB Vendor Id |
| +-----------------------------------------------------------------------------------+
| | USB Product Id |
+--> +-----------------------------------------------------------------------------------+
|
+--- Repeated 0 to MAX_USB_DEVICES(= 32) times
To Next Page
Loading...
Need help?
General
