RCDD Electronic Safety and Security (ESS) Systems

Question 1

What is the maximum channel length for an IP camera connected over twisted-pair Ethernet, without extenders?

Accepted Answer

100 m (328 ft)

Answer

Twisted-pair Ethernet channels (BASE-T) are limited to 100 m including patch cords. Cameras farther away need a fiber link, a media converter, or an extender.

Question 2

An electric door lock that unlocks when it loses power is called:

Accepted Answer

Fail-safe

Answer

A fail-safe lock, such as a magnetic lock, releases on power loss. A fail-secure lock stays locked. Which one to use depends on life-safety and egress requirements.

Question 3

Which change most directly reduces the storage and network bandwidth that a video surveillance system needs, at similar image quality?

Accepted Answer

Switching from H.264 to H.265 compression

Answer

H.265 (HEVC) typically cuts bitrate substantially compared with H.264 at comparable quality, which lowers bandwidth and storage needs. A higher frame rate or resolution increases bandwidth.

Question 4

A pan-tilt-zoom camera needs about 25 W at the device. Which PoE standard is the minimum that can power it?

Accepted Answer

IEEE 802.3at (Type 2)

Answer

802.3at (PoE+) provides at least 30 W at the PSE and 25.5 W at the powered device. 802.3af delivers only 12.95 W at the device.

Question 5

What is the main purpose of a Wiegand-protocol reader connection in an access control system?

Accepted Answer

Carrying credential data from the reader to the access control panel

Answer

Wiegand is a legacy reader-to-controller interface that carries credential data, typically over a multi-conductor shielded cable limited to about 150 m (500 ft). Locks and cameras are connected separately.

RCDD - Registered Communications Distribution Designer Practice Test

RCDD - Registered Communications Distribution Designer Practice Test

RCDD Electronic Safety and Security (ESS) Systems