Synchronization of applications in distributed systems using an asynchronous communication channel

• US 7,051,335 B2
• Filed: 12/27/2001
• Issued: 05/23/2006
• Est. Priority Date: 06/30/1999
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Talanis, Thomas, Gehring, Hubert, Plaum, Reiner
• Primary Examiner(s): EL HADY, NABIL M
• Application Number:
  US10/026,553
• Publication Number:
  US 20020087742A1
• Time in Patent Office: 1,608 Days
• Field of Search: 709/310, 719/313, 719/314, 719/315, 719/316, 719/330
• US Class Current: 719/315
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04L 67/133 Protocols for remote procedure calls [RPC]
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

A system and a method for transmitting data between a local data processing system and a remote data processing system through an asynchronous transmission channel. To ensure synchronization between a local and a remote data processing device, it is proposed that when a first program of the local data processing device sends a call, such as a RPC (Remote Procedure Call) to a second program of the remote data processing device, at least one predefinable parameter of the data to be transmitted is stored in the local data processing device. When the remote data processing device sends a response to the local data processing device, the predefinable parameter is provided to identify and/or synchronize the response in the first program.

Claims

1. A system for transmitting data between a local data processing device and a remote data processing device through an asynchronous transmission channel for use with distributed objects in the field of automation technology, said system comprising:

a memory assigned to the local data processing device for storing at least one user-specified parameter to identify a call sent by a first program of the local data processing device to a second program of the remote data processing device to solicit data from the second program of the remote data processing device;

means for integrating the user-specified parameter into response data sent by the remote data processing device to the local data processing device;

means for identifying the user-specified parameter in the response data;

means for synchronizing the response data such that by identifying the user-specified parameter in the response data, the response data of the second program of the remote data processing device is integrated into the first program of the local data processing device; and

an asynchronous transmission channel transmitting data between the local data processing device and the remote data processing device wherein the asynchronous transmission channel comprises a forward channel forwarding data from the local data processing device to the remote data processing device and a reverse channel forwarding the data from the remote data processing device to the local data processing device, wherein the forward channel and the reverse channel are not synchronized with each other.

2. A system as claimed in claim 1, further comprising:

means for comparing the stored specified parameter stored in said memory of the local data processing device with the user-specified parameter contained in the response data.

3. A system as claimed in claim 1, wherein the first program of the local data processing device is a user program and the second program of the remote data processing device is a server program.

4. A system as claimed in claim 1, wherein the system is used in the field of automation technology to operate and monitor programmable controllers.

5. A system as claimed in claim 4, wherein the program controllers are selected from the group comprising, stored program controllers, numerical controls and numeric drives.

6. A system as claimed in claim 1, wherein the specified parameter is formed at least from parts of the IDL (Interface Definition Language) and is transmitted by the first program to the second program.

7. A system as claimed in claim 1, wherein the system is used in connection with client applications in embedded systems.

8. A system as claimed in claim 7, wherein, the embedded systems are DCOM (Distributed Component Object Model) systems.

9. A system as claimed in claim 1, wherein the second data processing device stores the received from the first data processing device on a stack and restores the user-specified parameter before a callback is sent to the first data processing device.

10. A system as claimed in claim 1, wherein a user callback is constructed identically to an original call.

11. The system according to claim 1, wherein the forward channel functions independently from the reverse channel.

12. The system according to claim 1, wherein the local data processing device and the remote data processing device are configured to receive and send the data at the same time.

13. The system according to claim 1, wherein the call is sent separately from other calls of the local data processing device.

14. A method for transmitting data between a local data processing device and a remote data processing device through an asynchronous transmission channel for use with distributed objects in the field of automation technology, said method comprising:

integrating a user-specified parameter into a call of a first program of the local data processing device sent to a second program of the remote data processing device via the asynchronous transmission channel to solicit data from the second program, wherein the user-specified parameter identifies the call and is stored in the first data processing device;

integrating the user-specified parameter in the response data of the remote data processing device sent to the local data processing device via the asynchronous transmission channel in response to the call;

identifying the response data transmitted by the remote data processing device to the local data processing device in the first data processing device by observing the user-specified parameter;

integrating the response data by identifying the user-specified parameter into the first program of the local data processing device wherein the asynchronous transmission channel comprises a forward channel forwarding data from the local data processing device to the remote data processing device and a reverse channel forwarding the data from the remote data processing device to the local data processing device, wherein the forward channel and the reverse channel are not synchronized with each other.

15. A method as claimed in claim 14, further comprising:

comparing the parameter contained in the response data with the stored parameter.

16. A method as claimed in claim 14, wherein the user-specified parameter is formed at least from parts of the IDL (Interface Definition Language) transmitted by the first program to the second program.

17. A method as claimed in claim 14, wherein the method is used in connection with client applications in embedded systems.

18. A method as claimed in claim 14, wherein the embedded systems are DCOM (Distributed Component Object Model) systems.

19. A method as claimed in claim 17, wherein the second data processing device stores the user-specified parameter received from the first data processing device on a stack and restores the user-specified parameter before a callback is sent to the first data processing device.

20. A method as claimed claim 14, wherein a user callback is constructed identically to an original call.

21. An automation device comprising:

a local data processing device transmitting data through an asynchronous transmission channel for use with distributed objects in the field of automation technology;

a memory for storing at least one user specified-parameter to identify a call sent by a first program of the local data processing device to a second program of a remote data processing device to solicit data from the second program of the remote data processing device;

means for integrating the user-specified parameter in response data sent by the remote data processing device to the local data processing device;

means for identifying the user-specified parameter into the response data; and

means for synchronizing the response data such that by identifying the user-specified parameter in the response data, the response data of the second program of the remote data processing device is integrated into the first program of the local data processing device wherein the asynchronous transmission channel comprises a forward channel forwarding data from the local data processing device to the remote data processing device and a reverse channel forwarding the data from the remote data processing device to the local data processing device, wherein the forward channel and the reverse channel are not synchronized with each other.

22. An automation device as claimed in claim 21, further comprising:

means for comparing the parameter stored in memory of the local data processing device with the user-specified parameter contained in the response data.

23. An automation device as claimed in claim 21, wherein the first program of the local data processing device is a user program and the second program of the remote data processing device is a server program.

24. An automation device as claimed in claim 21, wherein the automation device is used in the field of automation technology to operate and monitor stored program controllers, numerical controls or numerical drives.

25. An automation device as claimed in claim 21, wherein the user-specified parameter is formed at least from parts of the IDL (Interface Definition Language) transmitted by the first program to the second program.

26. An automation device as claimed in claim 21, wherein the automation device is used in connection with client applications in embedded systems.

27. An automation device as claimed in claim 26, wherein the embedded systems are DCOM (Distributed Component Object Model) systems.