DCx Cameras
required for each camera by lowering the frame rate or the image size.
2.9.3 USB 2.0 Cabling and Connectors
In order to comply with the specifications, the maximum length of USB 2.0 cables is limited to 5 m. Longer cables
may be connected if you use high-quality material. The USB bus provides power supply with 5 V and 500 mA max.
Many USB devices use the bus power and do not need external power supply (bus-powered devices).
Cable design
The following illustration shows the basic design of a shielded USB cable:
D+/D-: data transfer
+5 V/GND: power supply
Connector types
On the PC side, USB 2.0 cables are equipped with a standard A type plug (four pins) and on the device side either
with a standard B plug (four pins) or a mini-B plug (five pins).
2.9.4 USB 3.0 Cabling and Connectors
In order to comply with the specifications, the maximum length of USB 3.0 cables is limited to 3-8 m. With the use
of repeaters cable lengths up to 20 m are possible. With signal conversion into optical signals cable lengths up to
100 m are possible. The USB bus provides power supply with 5 V and 900 mA max.
Cable design
The following illustration shows the basic design of a shielded USB cable:
SSTX+/-: SuperSpeed Transmit (data transfer from host to the device)
SSRX+/-: SuperSpeed Receive (data ransfer from device to the host)
D+/D-: data transfer (USB 2.0)
+5 V/GND: power supply
Connector types
On the PC side, USB 3.0 cables are equipped with a standard A type plug (8 pins) and on the device side either
with a standard B plug or a micro-B plug.
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Basic design of a USB cable
Basic design of a USB 3.0 cable
© 2013 Thorlabs GmbH