Specifications

Glossary
21
RADIA Lighting Control System
Glossary
Air Gap Switch - A relay or mechanical switch that physically separates a load from the power feed, resulting
in an air gap between the contacts. An air gap is a deliberate and noticeable space or disruption in a circuit
causing an open condition.
AxLink - A four-wire data bus used to transmit and receive data from the AxLink Central Controller to any of
255 devices on the system. An AxLink address designates which of 255 possible devices assigned to the main
AxLink is assigned to the Radia Lighting controller.
Ballast - An electrical device used in fluorescent and HID fixtures. It furnishes the necessary starting and
operating characteristics to the fluorescent lamp for proper performance. Not all ballasts can dim lights.
Fluorescent ballasts may contain the following:
Ballast reactor
Auto-transformer
Power factor correction circuit
Breaker - An automatic switch that stops the flow of electric current in a suddenly overloaded or otherwise
abnormally stressed electric circuit. A circuit breaker is an air gap switch.
BTU - The acronym for British Thermal Unit. This term also applies to the amount of heat required to increase
the temperature of a pound of water one degree Fahrenheit. It is used to measure the thermal or heat-producing
effect of a device.
CFL Lamp - An acronym for Compact Fluorescent Lamp (a type of fluorescent lamp).
Channel (Radia Lighting) - The Radia Lighting processor's dimming engine recognizes six independent
levels and paths of output control. These control paths are called dimming channels or just channels. Each
Radia Lighting master controller (pack) has six channels of control. AxLink channels are used in Axcess
programming and apply to operation using an AxLink system.
Choke - A device used in electric circuits to oppose changes in the magnitude or direction of current flow. A
choke device reduces noise caused by lamp filaments and is also known as a "de-buzzing coil."
Contact Closure - A circuit is formed when the two contacts of an open circuit are brought together. The
Radia Lighting master controller uses TTL logic levels normally pulled High to 5v. A closure to ground pulls
the level to logic Low and is read as a closure. Each of the eight closure inputs is independently operated and
controlled.
Contactor - A type of relay that accepts large current loads greater than 20 Amps, usually with a 120-volt
primary coil. A contactor is helpful in allowing a 120-volt control signal to switch a large circuit at 277 volts.
Control Card, also Card - A Radia Lighting master controller on a standard 2.75" x 10" enclosure plate that
is capable of six channels of control, an AxLink connection, a PROlink connection, and a dry closure
connection.
This applies to Radia Lighting models RDC-DC/120, RDC-DC/240, RDC-DC/277, RDC-PDC/120, and
RDC-PDC/240 only.
Control Current - The current used by a dimmer or switch to perform its function. Each Radia Lighting
controller supplies this current to its control ports and each Radia Lighting module uses and requires this
current in order to operate the dimmer or switch.
Control Port - The four-pin connector on the Radia Lighting controller used for electrical control of the
dimmer (or switch) is called the Control Port. All modules connect to a control port to operate. There is a
maximum of six ports on the Central Controller.
Controller - A Radia Lighting device capable of six channels of control, an AxLink connection, PROlink
connection, and a dry closure connection. A controller could also be the integrated module.
This applies to Radia Lighting models RDC-DC/120, RDC-DC/240, RDC-DC/277, RDC-PDC/120,
RDC-PDC/240, RDD-DM4/120, RDD-DM4/240, RDD-DM4/277, RDD-DM6/120, RDD-DM6/240,
and the RDD-DM6/277.
Curve - Used to match the channel level setting with the dimmer output. At a level of 50%, different curves
would cause different dimmer output voltages. A curve can be used to govern the amount of dimming control
relative to the level setting allowing for uniform dimming between different loads.
Dimmer - A device located in an enclosure that is capable of dimming a light or electric circuit. Each dimmer
is rated by Wattage and Voltage.