SATELLINE-3AS
User Guide, Version 2.3
25
reception 40 ms transmission 40 ms reception
3.6 Dual Band version
SATELLINE-3AS(d) radio modem is also available as a special "Dual Band" version. The radio
transceiver of the Dual Band version offers two times two MHz frequency bands, and radio
modem can be reprogrammed to operate at any channel within those two bands. Frequency
bands are tuned at the factory and the maximum separation between the highest and the lowest
frequency is 12 MHz (see the diagram on next page).
The centre frequency (fc) is set to the middle of the two frequency bands at the factory. When
using the SL-commands please note that SL&F=nnn.nnnn is the only command for frequency
change that works in all cases. (SL&+/-=nn command can be used only when the required
value for nn does not exceed 99.)
Max. 12 MHz
Max. 2 MHz fc
Max. 2 MHz
3.7 Dual Channel function
By setting the ”Dual Channel” function on, the SATELLINE-3AS radio modem can transmit and
receive data on separate channels. The radio modem is initially at the receive channel. Data
flow on the TD line starts automatically the frequency shifts to the transmit channel. The delay
caused by the frequency shift before the actual data transmission sequence is 40 ms, and the
same is needed for the return to the receive channel after transmission.
Band 1 (Active channel)
Band 2
Dual Channel
Transmit Channel
Receive Channel
Reverse Dual Channel
Receive Channel
Transmit Channel
The separation between the transmit and receive frequency is equal to the separation between
the lower limits of the specified frequency bands (Lower limit band 1 and Lower limit band 2).
NOTE!
SATELLINE-3AS(d) Dual Band is a special hardware version, and the frequency adjustment is
made case by case. Before starting the system design procedure please contact the
manufacturer for checking the technical details.
