Keri Systems SB-293 - Manual (Page 103)

Keri Systems, Inc. Technical Reference Manual – PXL-250 and SB-293
Revision 5.5 P/N: 01836-004 Page 103
RS-232 – a serial communication protocol for connecting data terminal devices. RS-
232 is the most commonly used communication protocol. It works best over shorter
distances.
RS-485 – a serial communication protocol for multi-drop communications. It is used
for higher speed and longer distance communications.
RTE – see REQUEST TO EXIT.
STAR PATTERN – multiple sets of daisy chained controllers all connected to the
master controller at the center of the star.
SUPPRESSION – the addition of a device to an electrical circuit that minimizes or
prevents transients from affecting the proper operation of that circuit.
TRANSIENT SUPPRESSOR – a device added to an electrical circuit that minimizes
the affects of transients.
TRANSIENTS – electrical surges or spikes conducted through power or data lines.
Transients are generated as electrical devices are turned on or off.
TRANSORB – an electrical suppression device. See SUPPRESSION.
WIEGAND COMPATIBLE DEVICES – a proprietary coding format for
information used by many of the suppliers of cards, key tags, proximity readers,
magnetic stripe readers, bar code readers, and related items.