Apparatus and method for communicating between devices trough use of a real time data base
DCFirst Claim
1. Apparatus for communicating between input/output devices each associated with at least one of a plurality of processes, comprising:
- a database memory comprising a plurality of memory elements, said memory elements operable to receive data from and transfer data to processes associated with said memory elements;
status circuitry associated with each memory element and further associated with at least one of said plurality of processes, said status circuitry operable to indicate that contents of a specific memory element have changed since a last previous transfer of data from said specific memory element to said processes; and
communication circuitry associated with the devices for transferring data from the database memory to the processes associated with said specific memory element in response to said status circuitry indicating a change in contents of said memory element.
3 Assignments
Litigations
0 Petitions
Reexaminations
Accused Products
Abstract
A control system (10) controls transfer of electronic signals to and from industrial and scientific equipment. The control system includes a real-time database (60) for storing data elements which may be accessed by a plurality of tasks (62, 64, 66, 68, 70, and 72). Each data element in the real-time database (60) has an associated changed status flag for each task which indicates whether the value of the element has changed since the last access by the task. Individual tasks must communicate through the real-time database, since no inter-task communication is supported. The tasks support bidirectional communication with industrial and scientific equipment, alarm supervision, data logging, real-time clock functions, mathematical and logical functions, and interactive operator communications.
226 Citations
20 Claims
-
1. Apparatus for communicating between input/output devices each associated with at least one of a plurality of processes, comprising:
-
a database memory comprising a plurality of memory elements, said memory elements operable to receive data from and transfer data to processes associated with said memory elements; status circuitry associated with each memory element and further associated with at least one of said plurality of processes, said status circuitry operable to indicate that contents of a specific memory element have changed since a last previous transfer of data from said specific memory element to said processes; and communication circuitry associated with the devices for transferring data from the database memory to the processes associated with said specific memory element in response to said status circuitry indicating a change in contents of said memory element. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 20)
-
-
11. A method for communicating between input/output devices each associated with at least one of a plurality of processes, comprising the steps of:
-
transferring data from at least one of the processes to at least one of a plurality of memory elements of a database memory upon completion of a process task; setting status bits associated with each memory element, each status bit associated with a unique process, said step of setting status bits occurring in response to a change in contents of a memory element as a result of said data transferring step; and transferring updated data from a specific memory element of the database memory to a requesting process when the status bit associated with the specific memory element and associated with the requesting process has been set, the requesting process performing a task in response to the updated data. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
-
-
19. A method for communicating between devices comprising the steps of:
-
transferring data from at least one of a plurality of local database memories to a main database memory independent of the local database memories, each local database memory associated with one of a plurality of devices, the devices providing a request to initiate said step of transferring data, the main database memory having a plurality of database memory elements and a plurality of status bits associated with each database memory element, each status bit further associated with a predetermined one of the devices; setting the status bits associated with each database memory element in response to a change in the contents of the database memory elements as a result of said step of transferring data; transferring updated data from the main database memory to at least one of a plurality of requesting local database memories, said step of transferring updated data occurring if the status bit associated with the device with which a particular local database memory is associated has been set.
-
Specification