THE BLUE BOX LT TECHNICAL GLOSSARY 143
LCDBBTG03Sept08
TECHNICAL GLOSSARY (Continued)
GROUP
Any given switch button, DI input or photocell input may
be programmed to control up to 8 relays. If more than 8
relays need to be programmed, or if any relay(s) need to
be controlled by a schedule, a Group must be used. There
are different types of groups available for programming.
Refer to the “Group Types” and “Groups FAQ” for details.
LAST INPUT OvERRIDE
When a command is sent to the DTC from a device which
will override any previous commands that may have been
sent to (e.g. if a switch button is used to turn a relay ON
and a photocell is programmed to control the same relay
and it detects a high light level, it will override the ON
command sent by the switch and turn OFF the lights).
LCP
Acronym for “Lighting Control Panel” - may be a master
or slave panel (e.g. Blue Box LT master or slave panel)
LOAD
Any device that requires power to operate (e.g. Lights);
and since loads are tied in to relays, the terms “load” and
“relay” are used interchangeably in this manual.
OCCUPANT SENSOR
Detects a person moving into a space to control relays.
Certain OCC sensors have dual technology sensing for
more reliable operation.
OSCILLOSCOPE
An electronic test device that allows signal voltages to
be viewed, usually as a two-dimensional graph of one or
more electrical potential differences (vertical axis), plotted
as a function of time or of some other voltage (horizontal
axis).
Refer to the “Oscilloscope testing procedure” on how to
use an oscilloscope with the bus to detect bad cables,
devices, misplaced or missing terminators.
PHOTOCELL
A device that measures the light intensity entering the
lens; photocells can be wired to the Blue Box LT to con-
trol relays throughout any of the first 8 time schedules.
SMACkER STRIP
Used to send a signal to control relays (Blue Box LT 16 only)
STABLE BUS
When all Cat. 5 cables are functioning and have been
crimped properly, both terminators are placed at the two
ends of the bus, and all devices are present on the bus and
communicating and functioning properly.
TERMINATOR
It is a jumper that completes a circuit by shorting a resis-
tor, placing it in parallel with the rest of the circuit. When
placed on the two end devices of a bus, terminators elimi-
nate signal reflections along the bus. If installed in the mid-
dle of the bus, it blocks signals from going past the point
where it is placed. Therefore, extra care must be taken to
not place a terminator anywhere except at the two end
devices on a bus.
TIME SCHEDULE
A programming option in the DTC that is used to turn
relays ON and OFF at specified times. Relays that need to
be controlled by a schedule must be placed in a group.
TRANSFORMER
Takes the high-voltage at the “primary side” terminals and
“steps-down” the voltage. In the case of a Blue Box LT,
the transformer accepts 120/277 V ac and outputs 20 V
ac between the outer terminals and 10 V ac between the
center and either of the two outer terminals.
To Next Page
Loading...
Need help?
General