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Transmission Modes
WAVECOM Decoder W74PC, W-PCI/e, W-CODE, W-CLOUD Manual V9.1.0
If an ALIS-2 system is identified the status line will display
System: “
XXXXXXXXh", where XXXXXXXXh
denotes an eight digit hex id string.
AMSAT-P3D
AMSAT (Radio Amateur Satellite Corporation) OSCAR-40 (AMSAT Phase 3D) is the latest satellite in the
Phase 3 series of high altitude radio amateur satellites.
The satellite telemetry system may be monitored.
Parameter
Value
Frequency range
VHF/UHF
Operation modes
FEC telemetry
Modulation
BPSK
Symbol rate
800 Bd (with Manchester coding)
Receiver settings
FM, BW = 5 kHz
Input format(s)
AF, IF
Additional Info
ITA-5
A complete telemetry frame consists of a 4 byte preamble, a 512 byte data set and a 2 byte CRC check-
sum. The 400 bps information is differentially encoded then EXORed with a 400 bps clock signal to create
a Manchester coded PSK signal.
The P3 flight computer of AMSAT OSCAR-40 uses a radiation hardened Cosmac CDP-1802 microprocessor
running at 100K instructions/sec. The operating system is called IPS, an acronym that translates as "In-
terpreter for Process Structures".
A small part of the computer’s 64 kBit memory is used by IPS as workspace. 256 bytes of data collected
via a 128 channel ADC, and 128 bytes of digital data is stored in this area called the IPS "SysPage".
The "SysPage" covers a lot of measurement functions: Status, navigation, power and temperature.
The decoder is able to demodulate, decode, verify (CRC) and display the data content in binary or as text.
The so called "A" or "E" packets are processed further and the information is displayed in four sections:
Main status, temperatures, power and sensors.
From
Options | Display Mode
, All frames or Error free frames may be selected.
Selecting
Options | Display
offers the option of an
ASCII
or
RAW
bits display.
APCO-25
Project 25 (P25) or APCO-25 is a set of standards for digital radio communications for public safety, secu-
rity, public service and commercial applications. It is standardized by Telecommunications Industry Asso-
ciation (TIA) and supports both voice and data transmissions. APCO-25 compliant technology is being de-
ployed in several phases. Wavecom decoder currently supports only Phase 1 systems.
Parameter
Value
Frequency range
VHF, UHF
Operation modes
Digital voice and data (Phase 1)
Symbol rate
4800 Bd
Modulation
Continuous 4 Level FM (C4FM) - CQPSK
Receiver settings
BW = 12.5 kHz
Input format(s)
IF
Access method
FDMA
