Remote terminal industrial control communication system
US5122948A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 28, 1990 |
| Grant date | Jun 16, 1992 |
| Priority date | — |
| Expiry date | Jun 28, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/21036
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An industrial control system has a central processing unit and a plurality of remote terminal units coupled to a communication network. Data is exchanged among the network devices in the form of messages which contain a source address, which designates the network address of the device that sent the message, and a destination address. Each of the remote terminal units stores a first network address assigned to the unit, and second network address corresponding to the network address of the originator of messages to which the remote terminal unit is to respond. The remote terminal unit processes only those messages in which both the destination address matches the first network address and the source address in the message matches the second network address. Thus multiple devices can be assigned the same first network address as long as each such device responds to a different source address. This enables more devices to be coupled to the network than the maximum number of allowable network addresses. Similarly multiple central processing units can be coupled to the network with access to a given remote terminal unit being restricted by the second address to messages originating fro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.