User's Manual

SATELLINE-4Pro
User Guide v0.93 DRAFT
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7.7 User data whitening
In some cases, if the user data includes a large number of constant characters, additional bit errors
may appear. The use of error correction (FEC) is recommended in such cases. If that is not possible,
the Data whitening feature can be used to improve the reliability of data transfer.
7.8 Pacific Crest and TRIMTALK compatibility
7.8.1 General
SATELLINE-4Pro radio modem supports additional to the original SATEL 3AS data transfer also:
 Pacific Crest compatible data transfer over the air, if the opponent Pacific Crest modems
operate in the transparent mode/FEC ON/Scrambling ON that is the most common setup
among RTK applications. The other modes are currently not supported.
 TRIMTALK
®
450s compatible data transfer over the air.
SATELLINE-4Pro radio modem provides the following radio compatibility settings:
 Pacific Crest 4-FSK modulation, Transparent mode/FEC ON/Scrambling ON.
 Pacific Crest GMSK modulation, Transparent mode/FEC ON/Scrambling ON.
 TRIMTALK GMSK modulation, Transparent mode
 TrimTalk450s(T) = TrimTalk450s GMSK (Rx fitted to Trimble transmitter)
 Pacific Crest-FST = Pacific Crest Transparent FST (4-FSK), FEC ON/Scrambling ON.
So far, only the transparent mode is implemented, since it is the most commonly used and
recommended by the user manuals. The ARQ based protocols with ACK/NACK schemes are not
preferred in RTK applications that apply one-way communication.
The implementation of Options 1, 2, 3 is based on the reference measurements and the available
public data of the following radio modems manufactured by Pacific Crest Corporation: RFM96W,
PDL HPB, PDL LPB. TRIMTALK is a trademark of Trimble Navigation Ltd.
NOTE!
All radio modems, which are to communicate with each other, must have the same setting for
Data whitening (ON or OFF). If the transmitting radio modem and the receiving radio modem
has different settings, data will not be received correctly.