ModemB

Project Context

For the automatic train return system project in Paris Porte de Chatillon, ClearSy developped the COPP system, in charge of opening and closing platform screen doors in this line 13 station.

Within the framework of the evolution of the COPP system, a new component called ModemB will be deployed, ensuring a more reliable communication and a better compatibility by adapting to the frequency requirements of several railway networks.

The latter aims to:

decode an analogue signal carrying information of varying degrees of complexity to a signal which carries information using baseband. (This baseband signalling can then be read by a PC system, or similar, via its series ports.)
pick up baseband information and modulate it to transmit it onto a physical medium (thin wire antenna, Hertzian, optical,..) according to several signal modulation techniques.

Our Actions

Expertise on M-FSK and M-PSK data transmission

Study of the performances of demodulation
Matlab simulation
Measurements of sounds and electrical disturbances
Modulation/demodulation algorithms.

Software development

DSP/BIOS coding in C and ASM
Modulation/demodulation algorithms

Hardware development

Electronic study & diagrams
Placing & Routing, Manufacture

Lab and ground tests and measurements

Sound tests
Limitation tests

Features of ModemB

Analogical emission/reception

Frequency range for reception [0 to 150Khz]
Maximum distance for emission/reception 3VCC
40dB out-of band rejection in the emission

CPU 200MHz
Memory:

IRAM 512Kb
SDRAM 16Mo
FLASH 4Mb

Mass storage: up to 4Gb on a SD card
Series communication

Transmission rate up to 115200 bauds
Protocol RS485, RS422, UART

16 TOR sink inputs or 16 TOR source outputs
Insulated or non insulated 9-25V supply