CLD Controls and Dimming 3

Question 1

DMX512 is a unidirectional protocol. What limitation does this create in a lighting control system?

Accepted Answer

The controller cannot receive feedback or status from fixtures

Answer

Because DMX512 is one-way (controller to fixtures), it provides no feedback path, so the controller cannot confirm fixture status, lamp failure, or actual output level.

Question 2

An RDM-enabled system extends DMX512 by adding which capability?

Accepted Answer

Bidirectional communication for device discovery and monitoring

Answer

RDM (Remote Device Management) adds a bidirectional layer to DMX512, enabling the controller to discover, configure, and receive status reports from fixtures.

Question 3

In a Lutron GRAFIK Eye QS system, what is the function of the 'fade time' parameter in a scene?

Accepted Answer

The time it takes for fixtures to transition from their current level to the scene level

Answer

Fade time defines how long fixtures take to smoothly transition from their current dimming level to the new preset level stored in the scene.

Question 4

Which wireless lighting control protocol operates in the 900 MHz band and is developed by Lutron for its Caseta and RadioRA product lines?

Accepted Answer

Clear Connect

Answer

Lutron's proprietary Clear Connect protocol operates in the 900 MHz band, offering better wall penetration and less interference than 2.4 GHz protocols.

Question 5

A lighting control network uses BACnet/IP. What is the primary reason a lighting designer would specify BACnet integration?

Accepted Answer

To allow the lighting system to communicate with the building's HVAC and BMS on a common platform

Answer

BACnet/IP allows the lighting control system to exchange data with the building management system (BMS), enabling coordinated control with HVAC, shading, and other building systems.

(CLD) Certified Lighting Designer Practice Test

(CLD) Certified Lighting Designer Practice Test

CLD Controls and Dimming 3