Version
3.3
16
4.2.1
RSSI-signal
The RSSI-signal (Received Signal Strength Indicator) gives an indication of the strength of the
received radio signal. This signal can be used to determine the approximate signal level. The
RSSI–signal can be set and read using the SL-command.
4.3
Error correction
The error correction mode is called the FEC-method (Forward Error Correction). When
activated, the FEC-function will cause the SATELLINE-M3-R1 and -M3-T1 to automatically add
additional error correction information, which increases the amount of transmitted data by 30 %.
It is used by the receiving radio modem to correct erroneous bits - as long as the ratio of correct
and erroneous bits is reasonable.
Error correction improves the reliability of data transfer via the radio interface especially in
unfavourable conditions. The FEC-function should be used when link distances are long and/or
if there are many disturbances in the radio channels used. The use of the FEC-function will,
however, decrease the data transfer throughput of data by about 30 %.
4.4
Error checking
When error checking is switched on, the radio modem will add a checksum to the transmitted
data. When the data is received, the checksums are verified before data is forwarded to the
serial port.
NOTE!
All radio modems that are to communicate with each other must have the same setting for
FEC (ON or OFF). If the transmitting radio modem and the receiving radio modem have
different settings, data will not be received correctly.