Usb Connectors And Cables - Smart Technologies Board 600 series Connection Manual

USB Connectors and Cables

USB Connectors
There are two types of full-size USB connectors: Series-A and Series-B. Either connector type can
be a receptacle or a plug.
• Series-A receptacles are used as outputs from host systems and hubs.
• Series-B receptacles are used as inputs to hubs or devices.
• Series-A plugs are always oriented towards the host system and mate with Series-A
receptacles.
• Series-B plugs are always oriented towards a USB hub or device and mate with Series-B
receptacles.
NOTE: Smaller versions of the Series-A and Series-B connectors, called Mini-A and Mini-B, and
Micro-A and Micro-B, are available and conform to the same rules as full-size USB connectors.
TIP: Although USB 2.0 Specifications requires that USB connectors can be "hot plugged" (i.e., you
can insert a USB connector with power on without damage to the circuitry), we recommend that
you connect all your devices and cables before you turn on the power. If you connect a device
when the power is already on, and the system doesn't work correctly, disconnect the power from
all active devices in the USB circuit, and then reconnect the power again.
USB Cables
For full-speed and high-speed connections, USB 2.0 Specifications allow two types of cable
assemblies:
• a standard detachable cable that is terminated on one end with a Series-A plug, and
terminated on the opposite end with a series "B" plug
• a captive cable that is terminated on one end with a Series-A plug, and has a vendor-specific
connection on the opposite end for the peripheral
Any other cable assemblies are prohibited.
Prohibited Cable Assemblies
The USB 2.0 Specifications prohibits specific cable assemblies. Prohibited cable assemblies may
work in some situations, but they cannot be guaranteed to work in all instances.
An example of a prohibited cable is the "extension cable". This type of cable assembly has a
Series-A plug and a Series-A receptacle or a Series-B plug and a Series-B receptacle. This
"passive" extension cable allows you to connect multiple cable segments, possibly exceeding the
maximum permissible cable length.
Another example of a prohibited cable is one with both ends terminated in either Series-A plugs or
Series-B receptacles, allowing two downstream ports to be connected together.
USB 2.0 Specification Primer 19