Specifications

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5502DAL C-Bus DALI Gateway Programming Guide

Group Addresses

Within the lighting applications, group addresses are used to emulate the function

of conventional wiring. The C-Bus addressing scheme allows you to have up to 255

groups. Each group is like a lighting circuit and can be controlled separately from

any other group.

A group association is programmed into both input units (key inputs and sensors)

and output units (relays and dimmers). Any message broadcast by the input units

for that group are read by the output units that share the same group address.

Loads are switched or dimmed as appropriate.

2.2 DALI

The DALI system uses both short addresses (analogous to unit addresses)

and group addresses (very similar to the C-Bus concept) to achieve a ﬂexible

assignment of loads to inputs.

The main differences between DALI and C-Bus are in the actual implementation of

group addresses and the nature of the commands broadcast over the DALI network.

DALI Group Addresses

The DALI units may have up to 16 group addresses each. This means that if

a unit has groups numbered 1,2,3 and 4 associated with it then it will respond

to a message addressed to group 1,2,3 or 4. Note that in a C-Bus system by

comparison, a load can only have one group address.

DALI Lighting Commands

The DALI system supports many commands that turn a load on or off, ramp it or

perform other functions. The controlled lighting ballast has a level and fade rate

programmed into it. The level and fade rate apply to any ramp command received by

the ballast, until such time as the parameters are changed by the DALI conﬁguration

software.

The level is not stored internally in the ballast, but the fade rate and fade time are.

Also stored in the ballast are parameters like power on level and mode level. The

current level is not stored, but is sent from C-Bus with each command.

There are two fade settings. The fade ‘rate’ and fade ‘time.’ The 5502DAL Gateway

uses the fade time setting.

In a C-Bus system each ramp command contains instructions for the level and fade

rate. A speciﬁed dimming ballast can generate the requested fade rate or level and

repeat the operation in rapid succession, each time at a different fade rate and level.

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