User's Manual

SATELLINE-3AS
User Guide, Version 2.2
21
3 RF INTERFACE
The Satelline-3AS(d) has a single TNC-type connector with impedance of 50 Ω. The Satelline-
3AS Epic model has two antenna connectors, the one on the left being both for transmitting
and receiving and , the one on the right being for receiving only.
When ordering the radio modem, the frequency band to which the radio modem will be tuned
to at the factory must be defined. The user can change the frequency of the radio modem
afterwards by ±1 MHz from the centre frequency (basic tuning range), or inside 2 X 2 MHz
frequency bands when using the special Dual Band version. Of course, all local regulations set
forth by the authorities must be taken into consideration. The 869 MHz model contains ten 25
kHz channels.
The data speed of the radio interface depends on the chosen radio channel spacing. A channel
spacing of 25 kHz enables a data speed of 19200 bps and a channel spacing of 12,5 kHz
enables, correspondingly, a data speed of 9600 bps. The data speed of the radio interface is
always fixed (19200 bps or 9600 bps) irrespective of the data speed of the serial interface. If the
data speeds of the radio interface and the serial interface differ from each other, the radio
modem will buffer the data in transfer temporarily, so no data loss will occur. The radio channel
spacing is set at the factory and cannot be changed afterwards.
3.1 Transmitter
The output power of the transmitter is adjustable. The greatest allowable power depends on
limits set by local authorities, which should not be exceeded under any circumstances. The
output power of the transmitter should be set to the smallest possible level which still ensures
error free connections under variable conditions. Large output power levels using short
connection distances can, in the worst case, cause disturbances to the overall operation of the
system.
OUTPUT POWER dBm 3AS 3AS 869 MHz 3AS Epic
10 mW +10
• •
20 mW +13
• •
50 mW +17
• •
100 mW +20
• •
200 mW +23
• •
500 mW +27
• •
1 W +30
•
•
2 W +33
•
5 W +37
•
10 W +40
•
Possible output power settings of the SATELLINE-3AS –line of radio modems.