Apparatus for controlling internetwork communications
US6321272A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 10, 1997 |
| Grant date | Nov 20, 2001 |
| Priority date | — |
| Expiry date | Sep 10, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P90/02
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An interface allows for the transfer of real time control data with guaranteed delivery times between devices on a general purpose network and an industrial control system. A proxy server takes the role of a TCP/IP router and is configured to control the rate at which messages are forwarded from the non-real time to the real time portion of the network, keeping the loading of the real time portion stable regardless of the external non-real-time communication demand. Real time data is preconfigured and exchanged in a regular sequence, with the cyclic update period known. The length of any communication message necessary to transmit this information, plus any sequencing and acknowledgment overhead, is calculated in advance and aggregated. Each device with authority to transmit on the shared medium is given a time budget, calculated so that the total transmission quantity in unit time is deliberately limited to some fraction of the maximum transmission capability of the network. All communication from devices whose traffic loadings cannot be so controlled is arranged to pass through the proxy device in order to gain access to the deterministic network, and the proxy enforces the budge…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.