Product manual

Spinpoint M9TU-USB 3.0 Product Manual REV 1.0
24
USB INTERFACE AND USB COMMANDS
6.2.1.2 Connector
To minimize end user termination problems, USB uses a “keyed connector” protocol. The physical
difference in the Series “A” and “B” connectors insures proper end user connectivity. The “A” connector is
the principle means of connecting USB devices directly to a host or to the downstream port of a hub. All
USB devices must have the standard Series “A” connector specified in this chapter. The “B” connector
allows device vendors to provide a standard detachable cable. This facilitates end user cable replacement.
Figure 6-2 illustrates the keyed connector protocol.
Figure 6-2: Keyed Connector Protocol
The following list explains how the plugs and receptacles can be mated:
Series “A” receptacle mates with a Series “A” plug. Electrically, Series “A” receptacles function as outputs from
host systems and/or hubs.
Series “A” plug mates with a Series “A” receptacle. The Series “A” plug always is oriented towards the host
system.
Series “B” receptacle mates with a Series “B” plug (male). Electrically, Series “B” receptacles function as inputs
to hubs or devices.
Series “B” plug mates with a Series “B” receptacle. The Series “B” plug is always oriented towards the USB hub
or device.
6.2.1.2.1 USB Connector Termination Data
Table 6-1 provides the standardized contact terminating assignments by number and electrical value for Series
“A” and Series “B” connectors.
Table 6-1: USB Connector Termination Data