Wavecom W61PC V7.5.0 - Manual (Page 142)

132  Transmission Modes WAVECOM Decoder W61PC/LAN Manual V7.5
The CODAN-9001 data transmission system uses a variable randomization in secure- and secure-
interactive mode. The randomization vector can change between successive transmissions. The randomi-
zation value is shown in the status pane. In the two status-lines at the top of the decoding window the
frame type (DATA, ACK, IDLE) and some information about the decompressor (if used) are presented.
Possible derandomization options:
 No derandomization - no manipulation of the demodulated symbols; in this case it is not possi-
ble to recognize frame characteristics and decode into TEXT DATA. Because the decoder does not
recognize the frame length, with every synchronization the maximum frame length is used for
decoding.
 Automatic LSR initialization (Secure and Unsecure) - handles both the secure and unsecure
transmission cases; an unsecure transmission is automatically recognized. In the secure case the
decoder calculates the start value.
 Custom-defined LSR initialization for derandomization - expects a seven-digit hexadecimal
value for initialization (note that it is important to enter leading zeros). This option should be
used if the initialization value is known, or if it is not possible to calculate the value automatically
due to poor signal conditions.
The CODAN-9001 decoder has the following output options:
 Store channel data. The channel data output is very useful for analysis purposes. In the channel
data output every channel packet is stored in a file.
(C:\Users\Public\Documents\WAVECOM\W61PC\Data-Output\CODAN9001[SN])
 Enable frame status messages. It is possible to activate frame status messages, with the rele-
vant checkbox. The frame status messages are printed in the decoder output. They show [PREAM-
BLE FOUND] and [EXTENDED PREAMBLE FOUND].
 Decompress. The user can control the decompressor and the channel data output. Please refer
the section Compressed Mode specifics for further information on Compressed Mode. The user can
set the decoder/decompressor into the initial state with the Mode-Resync button in the
WAVECOM Toolbar.
 RAW DATA - the output consists of synchronized and demodulated multichannel symbols in hex-
adecimal representation. Every symbol consists of 32 bits (16 channels * 2 bits/channel)
 TEXT DATA - the demodulator output is processed into readable text.
 TEXT & RAW DATA - if possible the decoder decodes into readable text, otherwise it outputs the
demodulated multichannel symbols as RAW DATA.
 7 or 8-bit-ASCII. CODAN-9001 can use a 7-bit or an 8-bit alphabet, the choice being made by
selecting the appropriate radio button. The 7-bit alphabet is often used in transmissions handled
by the CODAN-9102 software.
The data is presented in two ways: hexadecimal-form, and ASCII-form.