Simplex 4100U Application Manual page 93

Glossary of Terms,
Glossary
Continued
Bypass Pressure Control System – The bypass-around supply fan can actually be placed at any
level. The bypass duct dampers are controlled by one or more static pressure sensors located
between the stairtower and the building. In addition, a manually operated damper may be located
at the top of the stairtower for smoke purging by the Fire Department.
CC – Custom Control.
Central Station System – A system, or group of systems, in which the operations of circuits and
devices are signaled automatically to, recorded in, maintained, and supervised from an approved
central station having competent and experienced observers and operators who, upon receipt of a
signal, take the required action. Such systems are controlled and operated by a person, firm, or
corporation whose principal business is the furnishing and maintaining of supervised signaling
service.
Channel – A path for signal transmission between two or more stations or channel terminations.
A channel can consist wire, radio waves, or equivalent means of signal transmission.
Chimes – A single stroke or vibrating-type audible signal appliance that has a xylophone-type
striking bar.
Circuit Interface – A functional assembly that interfaces one or more of its initiating device
circuits with a signaling line circuit in a manner that permits the central supervising station to
indicate the status of each of its individual initiating device circuits.
Circuit – The conductors or radio channel, and associated equipment used to perform a definite
function in connection with an alarm system.
Coded Signal – A signal pulsed in a prescribed code for each round of transmission. A minimum
of three rounds and a minimum of three impulses are required for an alarm signal.
Combination Detector – A device that either (1) responds to more than one of the fire
phenomena such as smoke, heat, flame, and fire gas or (2) employs more than one operating
principle to sense one of these phenomena. Typical examples are (1) a combination of heat
detector with a smoke detector, or (2) a combination rate-of-rise and fixed temperature heat
detector.
Combination System – A local protective signaling system for fire alarm, supervisory, or guard
tour supervisory service whose components may be used in whole or in part in common with a
non-fire signaling system such as a paging system, a burglar alarm system, a musical program
system, or a process monitoring service system, without degradation of or hazard to the protective
signaling system.
Communication Channel – A signaling channel (usually leased from a communication utility
company) having two or more terminal locations and a suitable information handling capacity
depending on the characteristics of the system used. One terminal location is at the central
supervising station and the other terminal location or locations are sources from which are
transmitted alarm signals, supervisory signals, trouble signals, and such other signals as the central
supervising station is prepared to receive and interpret.
Compensated System – Adjust the airflow to make up for pressure lost through open doors.
A compensated system can use dampers (or vents) to relieve excess pressure in the stairtower to
ensure that the pressure does not go over the maximum limit.
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