Abstract: Controller capable of executing non-safety-related control logic. A safety module is added to the controller in order to increase the safety-integrity level of a control system. The controller is able to execute safety-related control of real-world objects. Such a control system may exist at an offshore production platform or in a hazardous area of a chemical plant.

Abstract: A method to revalidate a compiler intended for compilation of a user-written program for safety control in an industrial control system after it has been used. A test program is compiled a first time which test program is defined in a control language. The compiler is validated by verifying that the test program executes correctly. A first software is generated derived from the compiled test program intended for later comparison purposes. The test program is compiled a second time after the compilation of a user-written program. A second software is generated intended for a comparison based on the second compilation of the test program. The first software is compared with the second software, wherein the compiler is revalidated for any errors introduced between the first and the second compilation. Provided that the revalidation indicates no errors in the compiler, the user-written program is enabled to execute in a device with safety features for control of real world entities.

Abstract: A method to detect a fault in a CPU of an industrial controller during on-line safety control of real world objects. An application program is complied into assembler instructions. A test application is complied into assembler instructions where the assembler instructions is a subset of the total number of assembler instructions available for the CPU. The application program is downloaded and the test application to a central unit of an industrial controller. The test application is repeatedly executed in the industrial controller. A result from the test application is repeatedly compared with the pre-defined result in the test module. A fault detected in the CPU as the result from the test application does not equal the pre-defined result stored in the test module and the unexpected result of the test application is due to the execution of an assembler instruction of the test application.

Abstract: A method to detect a fault in a CPU of an industrial controller during on-line safety control of real world objects. An application program is complied into assembler instructions. A test application is complied into assembler instructions where the assembler instructions is a subset of the total number of assembler instructions available for the CPU. The application program is downloaded and the test application to a central unit of an industrial controller. The test application is repeatedly executed in the industrial controller. A result from the test application is repeatedly compared with the pre-defined result in the test module. A fault detected in the CPU as the result from the test application does not equal the pre-defined result stored in the test module and the unexpected result of the test application is due to the execution of an assembler instruction of the test application.

Abstract: Controller capable of executing non-safety-related control logic. A safety module is added to the controller in order to increase the safety-integrity level of a control system. The controller is able to execute safety-related control of real-world objects. Such a control system may exist at an offshore production platform or in a hazardous area of a chemical plant.

Abstract: A method to revalidate a compiler intended for compilation of a user-written program for safety control in an industrial control system after it has been used. A test program is compiled a first time which test program is defined in a control language. The compiler is validated by verifying that the test program executes correctly. A first software is generated derived from the compiled test program intended for later comparison purposes. The test program is compiled a second time after the compilation of a user-written program. A second software is generated intended for a comparison based on the second compilation of the test program. The first software is compared with the second software, wherein the compiler is revalidated for any errors introduced between the first and the second compilation. Provided that the revalidation indicates no errors in the compiler, the user-written program is enabled to execute in a device with safety features for control of real world entities.