BenQ PH460 Installation Handbook page 20

Term
Upstream
Downstream
Hub
Root hub
Speed (low-
speed, full-speed
and high-speed)
Active (self-
powered) device
Passive (bus-
powered) device
USB connectors and receptacles
USB connectors and receptacles are grouped into two types: Type-A and Type-B.
Standard
Mini
Micro
Standard
Mini
Micro
20 Cable extension guide
The direction of data transmission from a USB function to a host
or hub.
The direction of data transmission from a USB host or hub to a
function.
A USB device that provides upstream connection (port) to a host
and downstream connections (ports) to multiple functions.
A USB host that also performs the functions of a hub.
Three different speeds are currently defined in the USB 2.0
specification:
• Low-speed: data transmission at 1.5Mbps
• Full-speed: data transmission at 12Mbps
• High-speed: data transmission at 480Mbps
The actual transmission speed is determined by the device with
the lower (or lowest) speed. For example, if a low-speed
(1.5Mbps) USB peripheral is connected to a high-speed
(480Mbps) USB host, the maximum transmission speed between
these devices will be 1.5Mbps, not 480Mbps.
A USB device that has it own power supply and can operate
without the power supplied by the USB host.
A USB device that does not have its own power supply and solely
relies on the power supplied by the USB host.
• Type-A receptacles are used as outputs from host
Type-A
Connect Recepta
or cle
• Type-A plugs are always oriented towards the host
• Type-B receptacles are used as inputs to hubs or
Type-B
Connect Recepta
or cle
• Type-B plugs are always oriented towards a USB
Description/explanation
systems and hubs.
system and mate with Type-A receptacles.
devices.
hub or device and mate with Type-B receptacles.