Abstract

The Command Control Unit is a two way port allowing data flowing into it as commands in one direction while its result in the backward direction.

In actual case the data (command) flows into this Command Control Unit from a Personal computer (User) according to the requirements. These commands flow into the measuring end in one way and as a result the measured result is put back as the output of the Command Control Unit. The Command Control Unit pushes this output back to the Personal Computer (User).

But actually in the case of Chandrayaan-1 the user going along with the flight for inputting the commands is impracticable. So here we use a programmed Personal Computer (Stand Alone Controller) which acts itself as a Personal Computer giving the required instructions at times of needs. And also retrieve and handle the results appropriately. So the Stand Alone Controller forms the controlling factor of the Mass Spectrometer which we send in the flight along with the Mass Spectrometer.

The Stand Alone Controller which we program before being sent along with the flight contains the required instructions (commands) for controlling the Mass Spectrometer. So here we are developing a Command Control Unit Simulator which simulates the working of a Command Control Unit with which we could check the proper working of a Stand Alone Controller.

Description

The CCU simulator is a system which simulates the functions of Command Control Unit (CCU) of a mass spectrometer used for scientific experiments. CCU controls the functions of the mass spectrometer and then acquires the data of a mass scan and transmits them through the serial port. The CCU simulator is used to simulate three major functions of the CCU. This is required to test a Stand alone controller (SAC) which is a self programmed device sent to space. A Personal Computer used here is actually replaced by this SAC Unit. So CCU simulator is used in place of CCU to connect with SAC to test it.

The commands which we execute through this project work are

1. RESET followed by a booting process starting with E4
2. START SWEEP.
3. GET SWEEP DATA.

If an error in the command input is detected using the checksum then a negative acknowledgement is sent accordingly. The command will be identified and executed only if an error free command is sent.

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