Methods and systems for secure control of system modes and sub-modes

A control system comprising a control module and a plurality of sub-modules, wherein the control module is configured to exchange data with each of the plurality of sub-modules using a data structure comprising a plurality of bits, wherein each of the bits is capable of representing at least a first value or a second value, the data structure comprising:

• a first data field configured to represent a plurality of primary operating modes of the control system with a first portion of said bits, wherein each of the primary operating modes has a corresponding state of said first portion of bits selected such that no transition of any of said first portion of bits between said first value and said second value results in a state corresponding to another of said primary operating modes;
• a second data field configured to represent a plurality of module operating modes for at least one of said sub-modules with a second portion of said bits, wherein each of the module operating modes has a corresponding state of said second portion of bits selected such that no transition of any of said second portion of bits between said first value and said second value results in a state corresponding to another of said module operating modes;
• and
• a third data field configured to represent a designator for each of said sub-modules with a third portion of said bits, wherein each of the designators has a corresponding state of said third portion of bits selected such that no transition of any of said third portion of bits between said first value and said second value results in a state corresponding to another of said designators.

A method of robustly representing data a control system comprising a control module and a plurality of sub-modules using a data structure comprising a plurality of bits, wherein each of the bits is capable of representing at least a first value or a second value, the method comprising the steps of:

• designating one of a plurality of primary operating modes of said control system with a first portion of said bits, wherein each of the primary operating modes has a corresponding state of said first portion of bits selected such that no transition of any of said first portion of bits between said first value and said second value results in a state corresponding to another of said primary operating modes;
• designating one of a plurality of module operating modes for at least one of said sub-modules with a second portion of said bits, wherein each of the module operating modes has a corresponding state of said second portion of bits selected such that no transition of any of said second portion of bits between said first value and said second value results in a state corresponding to another of said module operating modes;
• and
• designating one of said plurality of sub-modules with a third portion of said bits, wherein each of the plurality of sub-modules has a corresponding designator of said third portion of bits selected such that no transition of any of said third portion of bits between said first value and said second value results in a state designating to another of said sub-modules.