Keri Systems SB-293 - Manual (Page 102)

Technical Reference Manual – PXL-250 and SB-293 Keri Systems, Inc.
Page 102 P/N: 01836-004 Revision 5.5
GLOBAL UNLOCK – a normally-open input (as programmed in the Doors32
program) that, when closed, generates a signal that unlocks all doors in the access
control network.
INPUT – an electronic sensor on the controller that detects a change of state in a
device outside the controller. See NORMALLY CLOSED, NORMALLY OPEN.
LOCK RELAY OUTPUT – a relay on the controller that changes its state upon
command by the controller. Typically the lock relay output unlocks a secure door.
NETWORK – a series of controllers linked together via a communication cable.
NORMALLY CLOSED – an input device that continually keeps a circuit active or
complete. A state change is generated when a normally closed device is opened. See
INPUT.
NORMALLY OPEN – an input device that continually keeps a circuit open or
incomplete. A state change is generated when a normally open device is closed. See
INPUT.
OUTPUT RELAY – a device that changes its state upon receiving a signal from the
controller. Typically the state change prompts an action outside of the controller such
as activating or inactivating a device.
PROXIMITY – a method of reading identification codes from cards or key tags that
require bringing the card or key tag within the proximity of a reader. No mechanical
interaction between card and reader is required for the reader to receive the
identification code.
READER – a device that "reads" an identification code from a card, key tag, magnetic
stripe, or related item.
RELAY, FORM C – a device that has both normally closed and normally open
circuits. When the relay is not energized, the normally closed circuit is complete and
the normally open circuit is open. When the relay is energized the circuits switch roles,
the normally closed circuit is open and the normally open circuit is complete. This
dual nature of Form C relays allows for two types of applications outside the
controller. A device may be attached to the normally closed circuit so that it is always
on until the relay energizes to open the circuit and turn it off. Or, a device may be
attached to the normally open circuit so that it is always off until the relay energizes to
turn it on.
REQUEST TO EXIT – a signal that informs the controller that someone has
requested egress from a secure area. RTE and REX are common abbreviations.
REX – see REQUEST TO EXIT.