Sierra Wireless DART 200 CDPD Modem manual RS-232, Registers

DART 200 CDPD Modem User’s GuideGlossary

PPP	Point-to-point protocol
	An alternative communications protocol used between
	computers, or between computers and routers on the
	Internet. An enhanced SLIP. See also, SLIP.
RC4	The encryption algorithm used by CDPD for data
	transmissions between the M-ES and the MDIS.
RF	Radio Frequency
RI	Ring Indicator
	One of the RS-232 signal lines. Not currently used by the
	DART.
RRM	Radio Resource Management

RS-232

RSSI

The process of managing CDPD channel acquisition, channel hopping, cell transfer, and transmitted signal strength.

An EIA hardware standard; it defines the most common type of serial communications port hardware. It covers signal definitions, pin assignments, voltage and impedance levels, and inter device-signaling rules.

Receive Signal Strength Indication

	The signal power level at the antenna of the modem,
	usually measured in dBm. See also, dBm.
RTS	Request To Send
	One of the RS-232 signal lines. Used in hardware flow
	control.
RTU	Remote Terminal Unit

RXD

SABME

S-Registers

Another name for a MAS; usually implies a fixed location telemetry device

Received Data

One of the RS-232 data lines.

Set Asynchronous Balanced Mode Extended

Sent by the M-ES as the first step in CDPD link establishment.

Status Registers

	A set of storage locations within the modem that hold
	status and control information for use by the modem
	firmware and the users application. Many can be set by
	the user when configuring the modem, or when activating
	diagnostic functions.
SER	Symbol Error Rate
	Percentage of symbols in error. See also, SIE.

Sierra Wireless, Inc. Glossary-6