Edwards Signaling 2400 Series - Manual (Page 61)

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10.3 Appendix 3 - Glossary
Alarm Silence/Reset Inhibit Timer - A panel option which prevents silencing Indicating Appliance Circuits
or resetting the panel for a programmed period after the last alarm.
Alarm Silence Timer - A panel option which automatically silences the Indicating Appliance Circuits
(IACs) after a programmed time limit after the last alarm.
Alert - A condition or state of an Initiating Device Circuit (IDC) caused when the effective internal
resistance of an initiating device is a relatively low impedance.
Alarm - A condition or state of an Initiating Device Circuit (IDC) caused when the effective internal
resistance of an initiating device is approaching 0
Ω .
Class A Supervision, IAC - Circuit monitoring technique which signals a trouble condition upon an open
or short condition on an Indicating Appliance Circuit. All appliances can operate in spite of an open fault.
Similar to Style Z supervision.
Class A Supervision, IDC - Circuit monitoring technique which signals a trouble condition upon an open
condition on an Initiating Device Circuit. All devices can initiate an alarm in the event of an open fault.
Class B Supervision, IAC - Circuit monitoring technique which signals a trouble condition upon an open
or short condition on an Indicating Appliance Circuit. Similar to Style Y supervision.
Class B Supervision, IDC - Circuit monitoring technique which signals a trouble condition upon an open
condition on an Initiating Device Circuit. All devices up to the location of an open fault can initiate an alarm.
Dialer - See digital alarm communicator transmitter.
Digital Alarm Communicator Receiver (DACR) - Central monitoring station equipment which receives
and displays messages from a digital alarm communicator transmitter (DACT) which are sent via the
public switched telephone network.
Digital Alarm Communicator Transmitter (DACT) - Equipment installed in the fire alarm panel which
transmits status changes to the central monitoring station by seizing a telephone line, dialing the
preselected number of the digital alarm communicator and transmit fire alarm panel status changes.
High Impedance Initiating Device - An alarm initiating device whose equivalent resistance will put an
Initiating Device Circuit in the Alert Mode.
Indicating Appliance Circuit (IAC) - A supervised output circuit connected directly to any audible or
visual signal appliance used to indicate a fire.
Initiating Device Circuit (IDC) - A supervised input circuit connected directly to any manual or automatic
initiating device whose normal operation results in an alarm or supervisory signal indication at the control
panel.
Low Impedance Initiating Device - An alarm initiating device whose equivalent resistance will put an
Initiating Device Circuit in the Alarm mode.
March Time - A 50% duty cycle, 120 beats/minute signal pattern.