Field Device with Separated Memory Areas

• US 20100125427A1
• Filed: 10/21/2009
• Published: 05/20/2010
• Est. Priority Date: 11/17/2008
• Status: Active Grant

• Current Assignee: VEGA Grieshaber KG (Grieshaber Verwaltungsgesellschaft mbH)
• Original Assignee: VEGA Grieshaber KG (Grieshaber Verwaltungsgesellschaft mbH)
• Inventors: Haas, Juergen, Motzer, Juergen, Lienhard, Juergen, GAISER, Martin
• Granted Patent: US 8,706,995 B2
• Time in Patent Office: Days
• US Class Current: 702/55
• CPC Class Codes: G01F 23/284 Electromagnetic waves
• CPC Class Codes: G01F 23/802 Particular electronic circuits for digital processing equipment
• CPC Class Codes: G01F 25/20 of apparatus for measuring liquid level
• CPC Class Codes: G01N 35/00871 Communications between instruments or with remote terminals
• CPC Class Codes: G01N 9/00 Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity
• CPC Class Codes: G06F 12/1416 by checking the object accessibility, e.g. type of access defined by the memory independently of subject rights G06F12/1458 takes precedence

Abstract

A field device for measuring a filling level, a pressure or a density of a medium in a container includes data memory with two memory areas that are separated from one another. First data for safety-critical program modules is stored in the first memory area. Second data for safety-uncritical program modules is stored in the second memory area. The two memory areas are separated from one another. All access to these memory areas is controlled by a memory management unit.

Claims

1. A field device for measuring one of a filling level, a pressure and a density of a medium in a container, comprising:

a data memory storing data of program modules, the data memory including at least two memory areas;

a first memory area and a second memory area, the first area being separated from the second area,

wherein the data of program modules includes first data and second data, the first data being is required for a safe operation of the field device and categorized as safety-critical, the second data not being required for the safe operation of the field device and categorized as safety-uncritical, and

wherein the first memory area stores the first data and the second memory area only stores the second data.

2. The field device of claim 1, wherein the separation of the first and second areas is realized in such a way that none of the data stored in the first area can be unintentionally altered because the program modules that are categorized as safety-uncritical do not have access to the data.

3. The field device of claim 2, further comprising:

a memory management unit,

wherein the separation of the first and second areas is realized in such a way that the memory management unit manages all access to the data.

4. The field device of claim 3, wherein a real-time operating system is provided that corresponds to safety requirements of the field device and supports the memory management unit.

5. The field device of claim 4, wherein the operating system allows communications between the program modules.

6. The field device of claim 1, wherein the first area includes a data memory of a first program module that is designed for executing a function that is selected from the group comprising at least one of determination of measured values as a function of sensor measuring data, derivation of additional measured values as a function of already determined measured values, output of measured values and diagnosis.

7. The field device of claim 1, wherein the second area includes a data memory of a second program module that is designed for executing a function that is selected from the group comprising at least one of establishing a connection with an external communication unit, recording measured values with status information as a function of the time, indicating measured values and adjusting values in the field device.

8. The field device of claim 6, wherein the field device cyclically processes the determination of measured values, the derivation of measured values and the output of measured values.

9. The field device of claim 8, further comprising:

a measured value recorder,

wherein the field device determining the diagnosis parallel to the acquisition of measured values, the measured value recorder checking after each determination of a measured value if the corresponding measured value needs to be recorded; and

wherein the measured value is stored in the first area and the second area.

10. The field device of claim 1, wherein the field device includes one of a filling level radar, an ultrasonic level measuring device and a limit level measuring device.

11. The field device of claim 1, wherein the first area stores the first data and first program modules that are required for the safe operation of the field device and categorized as a safety-critical;

and wherein the second memory area only stores the second data and second program modules that are not required for the safe operation of the field device and categorized as safety-uncritical.

12. A method for measuring and determining one of a filling level, a pressure and a density of a medium in a container using a field device, comprising:

executing first program modules that are required for a safe operation of the field device and categorized as safety-critical, first data relating to the first program modules being stored in a first memory area of a data memory; and

executing second program modules that are not required for the safe operation of the field device and categorized as safety-uncritical, second data relating to the second program modules being stored in a second memory area of the data memory,

wherein the first area is separated from the second area.

13. The method of claim 12, further comprising:

initiating a communication between the first and second areas using an operating system that corresponds to safety requirements of the field device.

14. A program element for measuring and determining one of a filling level, a pressure and a density of a medium in a container using a field device, wherein the program element instructs a processor to carry out the following steps when it is executed on the processor:

executing first program modules that are required for the safe operation of the field device and categorized as safety-critical, first data relating to the first program modules being stored in a first memory area of a data memory; and

executing second program modules that are not required for the safe operation of the field device and categorized as safety-uncritical, second data relating to the second program modules being stored in a second memory area of the data memory,

wherein the first area is separated from the second area.

15. A machine-readable medium, on which a program element for measuring and determining one of a level, a pressure and a density of a medium in a container using a field device is stored, wherein the program element instructs a processor to carry out the following steps when it is executed on the processor:

executing first program modules that are required for the safe operation of the field device and categorized as safety-critical, first data relating to the first program modules being stored in a first memory area of a data memory; and

executing second program modules that are not required for the safe operation of the field device and categorized as safety-uncritical, second data relating to the second program modules being stored in a second memory area of the data memory,

wherein the first area is separated from the second area.