Plant information management system

• US 20020188366A1
• Filed: 05/09/2002
• Published: 12/12/2002
• Est. Priority Date: 05/10/2001
• Status: Active Grant

• Current Assignee: Automsoft R & D Limited
• Original Assignee: Automsoft R & D Limited
• Inventors: Pepper, Ian Anthony, Cagney, Austin, Prylowski, Anthony
• Granted Patent: US 7,155,450 B2
• Time in Patent Office: Days
• US Class Current: 700/108
• CPC Class Codes: G06Q 10/06 Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

In a plant information management system (PIMS, 1), data received from a process device (PCC, 10) is cached by a data logger (2) in blocks. A database controller (4) receives, for each data event, a time string, a value string, and a data quality indicator. The quality indicator is stored by exception only (if “bad”). MSBs of the time string are encoded in a hierarchical database structure of item (process device)—year—day levels. LSBs of the time string, the value string, and quality exceptions are stored as event objects in linked list arrays referenced to a day array object. There is thus no need for an index and the structure provides hierarchical compression.

Claims

1. A data capture system for a plant information management system, the data capture system comprising:

a data logger (2) comprising means for interfacing with a process device to receive process data in real time,

a database controller (4) comprising means for storing said data, characterised in that,

the database controller comprises means for storing the data in a time-encoded hierarchical object structure (3) with successive hierarchical levels (20-23) associated with shorter time periods.

2. A data capture system as claimed in claim 1, wherein the database controller (4) comprises means for storing data for each measuring point as an event object in lowermost levels (23) of the hierarchical structure.

3. A data capture system as claimed in claim 1, wherein the database controller (4) comprises means for storing the data in linked list arrays.

4. A data capture system as claimed in claim 1, wherein the database controller (4) comprises means for storing item objects at an upper hierarchical level, each said item object being associated with a particular process device.

5. A data capture system as claimed in claim 4, wherein the database controller (4) comprises means for storing a year array object (21) linked to each item object (20), said year object (21) comprising an array of references to day array objects.

6. A data capture system as claimed in claim 5, wherein the database controller (4) comprises means for storing an event bucket (23) linked with each day array object, said event bucket comprising linked list arrays of data event objects.

7. A data capture system as claimed in claim 1, wherein the data logger (2) comprises means for determining quality of a data event, and for associating a quality indicator with the data event.

8. A data capture system as claimed in claim 7, wherein the database controller (4) comprises means for storing the quality indicator only if it is exceptional.

9. A data capture system as claimed in claim 8, wherein the database controller comprises means for storing an event object as time and value strings in one array 23(b) and exceptional quality indicators in a linked array 23(c).

10. A data capture system as claimed in claim 1, wherein the database controller (4) comprises means for defining the database structure according to a breakdown of bits of a time value for a data event, with most significant bits being associated with higher hierarchical levels.

11. A data capture system as claimed in claim 10, wherein the database controller (4) comprises means for storing only least significant bits of the time value in the data event, the most significant bits being encoded in the database hierarchical structure.

12. A data capture system as claimed in claim 1, wherein the data logger (2) comprises means for caching received event data.

13. A data capture system as claimed in claim 12, wherein the data logger (2) comprises means for caching the event data intact in blocks which are linked list structures.

14. A data capture system as claimed in claim 13, wherein the data logger (2) comprises means for allocating a fresh linked list initially and for subsequently transferring flushed blocks to the fresh linked list to avoid the need to destroy flushed blocks and create fresh blocks after a data flush operation.

15. A data capture system as claimed in claim 1, wherein the data logger (2) comprises means for inserting a time stamp in each block of the fresh linked list and for periodically destroying blocks which have been unused for a time period exceeding a threshold.

16. A plant information management system comprising a data capture system as claimed in claim 1.

17. A computer program product comprising software code for performing operations of a data capture system as claimed in claim 1 when executing on a digital computer.