SATELLINE-2ASxE
User Guide, Version 2.0
15
3.1.1 Special BREAK Character
A BREAK character is used in some special protocols e.g. ABB RCOM protocol. The BREAK
character is the first character of the data string with 0 level. It is longer than one normal
asynchronous character.
BREAK
DATA
The transmitting radio modem recognises the special start element, BREAK, at the beginning of a
data string. At reception side the radio modem generates a BREAK in a similar position. The exact
length of the BREAK character is not transmitted.
3.2 Data speed
The data speed of the SATELLINE-2ASxE is
1200 - 9600 bit/s
with the channel spacing of 25 kHz
and 1200 - 4800 bit/s with the channel spacing of 12.5 and 20 kHz respectively.
The data speed can be selected in the programming mode.
4 Repeater Station Using One Radio Modem
Short data packets of 135 B maximum can be repeated using one radio modem. The repeater
function has to be set on in the programming mode. In the repeater mode the radio modem works
as an independent unit. When a radio modem is only used as a repeater it only requires a power
supply and an antenna. No other equipment is needed.
A radio modem working as a repeater can also be used for transmission and reception of data. In
the repeater mode the radio modem receives data in the same way as usual. However, at the same
time it memorizes the received data. After finishing the reception of data the radio modem does not
turn back to the state where it observes the interface lines. It immediately transmits the received and
memorized data on the same channel and with the same settings as received. When transmitting
data from the RS-line the functions of the radio modem do not differ from a normal radio modem.
There can be several repeaters in the same system and under the same base station. The repeater
stations can also be grouped in a chain, wherein the message goes via several repeater stations. It
is necessary to use addresses of the radio modem in a system with several repeater stations.
