Field device

A field device comprising:

• a program executor configured to perform a calculation using a detected value;
• a memory comprising
• a first data buffer area configured to store data based on the detected value,
• a second data buffer area configured to store the data based on the detected value,
• a first program area configured to store a first program causing the program executor to perform a calculation using the data stored in the first data buffer area,
• a second program area configured to store a second program causing the program executor to perform a calculation using the data stored in the second data buffer, the second program designed such that if same data is used for the calculation, a result of the calculation performed according to the second program is the same as a result of the calculation performed according to the first program,
• a first program buffer area configured to store intermediate data when the program executor executes the first program,
• a second program buffer area configured to store intermediate data when the program executor executes the second program,
• a first calculation result storage buffer configured to store a result of the calculation performed by the program executor according to the first program, and
• a second calculation result storage buffer configured to store a result of the calculation performed by the program executor according to the second program;
• and
• a calculation result comparator configured to compare the calculation result stored in the first calculation result storage buffer with the calculation result stored in the second calculation result storage buffer by determining whether the calculation result stored in the first calculation result storage buffer matches the calculation result stored in the second calculation result storage buffer,
• wherein, in response to the calculation result stored in the first calculation result storage buffer matching the calculation result stored in the second calculation result storage buffer, the calculation result comparator determines that a soundness of the memory is maintained.

A field device comprising:

• a program executor configured to perform a calculation using a detected value;
• a memory comprising
• a data buffer area configured to store data based on the detected value,
• a program area configured to store a program causing the program executor to repeatedly perform a calculation twice using the data,
• a first program buffer area configured to store intermediate data when the program executor executes the program a first time,
• a second program buffer area configured to store intermediate data when the program executor executes the program a second time,
• a first calculation result storage buffer configured to store a result of the calculation performed by the program executor the first time according to the program, and
• a second calculation result storage buffer configured to store a result of the calculation performed by the program executor the second time according to the program;
• and
• a calculation result comparator configured to compare the calculation result stored in the first calculation result storage buffer with the calculation result stored in the second calculation result storage buffer by determining whether the calculation result stored in the first calculation result storage buffer matches the calculation result stored in the second calculation result storage buffer,
• wherein, in response to the calculation result stored in the first calculation result storage buffer matching the calculation result stored in the second calculation result storage buffer, the calculation result comparator determines that a soundness of the memory is maintained.