Telemery Data Acqusition & Transmission System
Pulse Code Modulation (PCM) Encoder
Telemetry plays very important role in any missile development program by monitoring various missile sub systems during flight. It measures various physical and electrical parameters and is transmitted to ground. From this data, performance of all missile sub systems will be evaluated.Telemtry system consists of sensors. Signal conditioners, PCM encoder and Antenna system.
Analog signals from signal conditioner unit (after amplification, signal conditioning and filtering) will be fed to PCM encoder, which will be sampled and converted to 8 bit digital data. This data along with the direct digital data from OBP will be interleaved with frame sync words and sub frame sync words in a digital multiplexer.
The data at the output of the digital multiplexer is of serial form and is code converted NRZ-L to BIΦ-L code.
This data will be passed through a Bessel low pass filter of cutoff frequency 1.4 MHz to restrict the bandwidth of the signal before modulation.
The filter output from the PCM ENCODER will be modulated using an S-Band Transmitter. The output of FM Transmitter will be radiated through an antenna system (Quadra pole-monopole of λ/4 length) from onboard to ground.
This RF signal will be received by a ground telemetry receiving station and will be recorded/stored in magnetic tapes and PC’s.
Features
 |
SC6803 – ASIC FOR PCM |
|
512 K UV-EPROM is used as Program memory |
|
512 K UV-EPROM is used for the data storage |
|
Quadruple differential driver |
|
Quad bus buffers |
|
Quad high precision op-amp |
|
Synchronous 4-bit up/down counter |
|
4 MHZ, 25ppm crystal oscillator |
Applications
Vital role in telemetry system in any missile development programs. |
