WAVECOM Decoder W74PC, W-PCI/e, W-CODE, W-CLOUD Manual V9.1.0
Transmission Modes
145
CLOVER-2500
CLOVER-2500 is almost identical to CLOVER-2000. The only differencies are as follows:
Baudrate: 78.125 Bd (CLOVER-2000: 62.5 Bd)
Spacing: 312.5 Hz (CLOVER-2000: 250 Hz)
Center: 1562.5 Hz (CLOVER-2000: 1500 Hz)
Otherwise the mode has the same features as CLOVER-2000.
CODAN-SELCAL
The mode was developed by the Australian CODAN PTY. and is very similar to GMDSS/DSC.
Parameter
Value
Frequency range
HF
Operation modes
Digital Selcal
Modulation
FSK
Symbol rate
100.0 Bd
Receiver settings
DATA, CW, LSB or USB
Input format(s)
AF, IF
Additional Info
ITU R M.493 alphabet
CODAN SELCAL operates with 100.0 Bd and can be started by selecting the mode.
A preamble of at least 100 dot reversals, which are 50 changes between "0" and "1" (low and high bit),
precedes the data block. This lead-in has duration of 2.0 seconds. Digital MARK "1" is represented by a
frequency of 1870 Hz and SPACE by 1700 Hz.
The dot pattern is followed by a word synchronization sequence called the "phasing preamble". The char-
acters no. 125 and no. 108 are alternately transmitted for 1.2 seconds.
This sequence is followed by the data block with different control characters and the message. Each data
byte consists of 7 data bits and 3 parity bits. Thus the duration of each character is 100 ms.
Selecting
Options | Display
offers the option of an
ASCII
or
RAW
bits display.
CODAN-3212
CODAN-3212 is an HF transmission mode defined and developed by the same named Australian company.
CODAN-3212 HF Data Station:
The CODAN-3212 HF data modem provides a robust method of data
communication over an HF path. A standard CODAN-3212 HF data station comprises a CODAN-3212 HF
transceiver, which is capable of high-speed data transfer, an antenna system, a 12 V DC power supply, a
CODAN-3212 HF data modem and a PC with terminal software. The connection between the PC and the
CODAN-3212 modem can be established via an Ethernet connection or by connecting a cable between a
serial COM port on the PC and the DATA connector on the modem. The data is passed from the terminal
software of a PC to the CODAN-3212 HF data modem. It is processed by the modem and then sent to the
CODAN-3212 HF transceiver for transfer via HF to the other CODAN-3212 transceivers. At the receiving
node, the data is passed from the transceiver to the modem, where it is decoded and displayed at the
terminal software of the remote PC. All modems need to be set such that they use the same high-speed
waveform. There are two possibilities to send data between CODAN-3212 modems. Either by a broadcast
connection or by a peer-to-peer connection. The difference between these two connections is that in a
peer-to-peer connection only two modems can be addressed, whereas in a broadcast connection all mo-
dems within a certain address range can be addressed. In a peer-to-peer connection the receiving node
needs an explicit confirmation from the sending node that the data has arrived, whereas in a broadcast
connection the receiving node does not need an explicit confirmation. The transceivers of the addressed
CODAN-3212 modems need to be set to the same channel, in order to process the data from the sending
modem. Additionally, in a peer-to-peer connection the data can be sent with a compression, which is not
