Patent ID: 7813820

Claim:
A method to increase a safety integrity level of a single controller for control of real world objects, the method comprising: attaching to the single controller a safety-hardware unit wherein the safety-hardware unit communicates with a central processing unit of the single controller, wherein the safety-hardware unit is used only for safety-critical control, connecting a bus to the single controller and connecting an input/output unit to the bus, downloading safety-related configuration data and/or diagnostic information to the attached safety-hardware unit and downloading a control function software to the single controller, configuring the attached safety-hardware unit to execute logic, which depends on the downloaded safety-related configuration data and/or diagnostic information, actively or passively setting output values of the single controller to a safe state for online safety control, obtaining access to a plurality of input and output values of a real world object through the bus, and verifying a validity of bus communication with the attached safety hardware unit.