User`s manual

DVI 201 and HDMI 201 Tx/Rx • Installation and Operation
Installation and Operation, cont’d
2-22
DVI 201 and HDMI 201 Tx/Rx
A
Appendix A
Reference Information
Specifi cations
Part Numbers
• High-bandwidth Digital Content Protection (HDCP) is
an encryption method that protects copyrighted digital
entertainment material that uses DVI video.
 HDCP is generated by video player hardware,
enabled by the video content.
 The HDCP key is transmitted with the Display Data
Channel (DDC).
 The DDC signal line was designed for the DDC’s low
data rate; the HDCP key rate is much higher.
♦ Without active buffering, an HDCP key signal
can travel only a short distance. The display
may properly receive the digital video signal, but
not the HDCP key. Without the key, the display
cannot decrypt the video signal. Symptoms of
undecrypted video may include a fl ashing black
or blue screen or “snow”.
♦ With active buffering, an HDCP key signal can
travel as far as other signals to ensure proper
decryption.
♦ The DVI 201 and the HDMI 201 actively buffer
the HDCP key.
Troubleshooting
DVI/HDMI signals run at a very high frequency and are
especially susceptible to bad video connections, too many
adapters, or cables that are too long. To avoid the loss of an
image or introduction of image jitter, follow these guidelines:
• The DVI/HDMI cable on the input to the transmitter or
the output of the receiver should not exceed 10' (3 meters).
• Use only cable designed for DVI/HDMI signals.
• Limit or avoid the use of adapters.
• If the display exhibits a fl ashing black or blue screen,
snow, or other distortion, a non-HDCP compliant display
may be receiving an HDCP-encrypted signal.
Check for an HDCP problem by ejecting the DVD from
the player. If the display distortion stops and the DVD
menu or screensaver image is clear, the problem is
HDCP-related.