user manual

15-3
User Guide for Cisco Digital Media Manager 5.4.x
OL-15762-05
Chapter 15 Touchscreens, Projectors, and Displays
Concepts
Understand How to Choose Media Signal Cables
Caution Poorly shielded cable can sometimes promote undesired signal leakage ( egress ), interference from over-the-air
signals ( ingress ), or crosstalk between cables that are in close physical proximity.
Special considerations apply when you obtain a signal cable that is longer or of a different type than
cables that we included in your product kit. For DMP models that support the following signal cable
types, the maximum supported lengths are:
• Composite— 10 ft (approximately 3 m)
• HDMI 1.1—16 ft (approximately 5 m)
• RCA — 10 ft (approximately 3 m)
• S-Video —10 ft (approximately 3 m)
• SPDIF —10 ft (approximately 3 m)
Note • When image signals are transmitted through a composite cable, image quality suffers. When you use a composite
cable and your DMP shows any web-based media, small text might be difficult to read in TVzilla (the web browser that runs
on some DMP models). To work around this limitation, you can lower the browser resolution setting in DMPDM.
• Shockwave Flash (SWF) text is blurred during playback when a component video cable connects your DMP to
its presentation system (CSCsx48899). To work around this limitation, avoid the use of component video cable.
Cable Quality
The best signal cables objectively are those with the lowest signal resistance. Factors that affect signal
resistance include wire gauge, cable shielding quality, and cable connector quality. However, the same
materials and engineering designs that reduce signal resistance add to the cost of manufacturing. This
added cost is passed along to a consumer. So, it is useful to understand when signal resistance is not
relevant. Knowing this can help you to manage and reduce expenses without necessarily lowering
your standards. High cost is not inevitable. Nor is it proof of high quality. Sometimes, in fact, high
quality (low signal resistance) is irrelevant.
Even mediocre signal cables are sometimes sufficient, and such cables are often very affordable.
Figure 15-1 illustrates the most important factors to consider when you choose signal cables.