Specifications

Crestron DigitalMedia™ Design Guide
42 Check website (www.crestron.com) for product availability
Appendix A - The Device List
HDCP Limits in Source Devices
All HDMI sources that utilize HDCP limit the
number of devices that may be connected at any
given time. An important aspect of HDCP is its use
of “keys” to manage the handshaking that occurs
between any two devices.
Every HDMI source device has a limit to the
number of downstream devices it can support,
determined by the number of available HDCP keys,
while simultaneously limiting the depth of devices
in the signal path.
Too many devices or greater-than-allowed depth
in a signal path (from source to display) may create
problems with displaying of audio and video
content.
The HDCP specification states that the maximum
depth of devices between source and display is
six. Connecting too many displays or processors
causes the source to simply stop outputting a
signal without warning.
To prevent failures, DigitalMedia tests the HDCP
limits of each HDMI source, allowing the installer
to configure the system around any limitations,
or substitute a different component.
This diagram presents a few possibilities to
illustrate the HDCP key and device depth
limitations.
NOTE: Room Media Controllers and Repeaters do
not require HDCP Keys and do not count as
devices.