SATELLINE-3AS and SATELLINE-3ASd
11
RSSI = Received Signal Strength Indicator, can be used for monitoring the signal quality with a
DTE.
CTS = Clear To Send, used in handshaking. Indicates when the radio modem is ready to accept
data on the TD line.
SGND = Signal GrouND. Can be connected to GND.
RD = Receive Data. Data from the radio modem to the DTE.
DSR = Data Set Ready. Indicates "ON" state of the modem. The signal level is the same as the
DTR signal level.
TD = Transmit Data. Data from the DTE to the radio modem.
RTS = Request To Send, used in handshake. The DTE usually enables RTS when it is ready to
receive data. NOT IMPLEMENTED in the radio modem.
CD = Carrier Detect. Indicates a strong signal on the radio channel, can be used to avoid data
collisions on the radio channel.
DTR = Data Terminal Ready, when connected to the operating voltage (V
b
) the radio modem is
ON, when not connected (NC) the radio modem is in the STAND-BY mode
MODE = selects the DATA mode if not connected, and SETUP mode if grounded. SETUP mode
is only needed when installing the radio modem, usually the radio modem is always in the DATA
mode.
V
b
= Operating voltage.
5.1.1.2
RS-232 Interface
RS-232
standardises serial communication between computers and between computer terminals
and modems. Most applications use the RS-232 standard for interfacing peripherals to personal
computers. RS-232 uses transmission lines in which the state of each signal is represented by
referencing the voltage level of a single line to ground. RS-232 was designed for serial
communication cable up to distances of 15 m. RS-232 is implemented differently in different
peripherals so all peripherals using RS-232 are not necessarily compatible. (See also paragraph
7.2.1 for wiring).
