Ad-hoc synchronization of industrial control networks
US9323286B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 22, 2012 |
| Grant date | Apr 26, 2016 |
| Priority date | — |
| Expiry date | Mar 30, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B19/05
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A method and apparatus are disclosed to provide ad-hoc synchronization in industrial networks between a programmable logic controller and each I/O device without any specific protocol extensions or distributed clock scheme. An embodiment of an industrial control network comprising a Programmable Logic Controller (PLC), a network coupled to the PLC, and a plurality of networked input/output (I/O) devices coupled to the network is provided. Each I/O device comprises: inputs coupled to the network to receive data from the PLC as device input data; and outputs coupled to the network to transmit output data from the I/O device to the PLC. The embodiment further comprises a programmable timer initiating an I/O cycle for the device on a periodic basis. The I/O device is operable to determine a first time period starting at the time at which specific output data arrives from the PLC and ending when the period of the timer ends. The first time period is compared to a predetermined time period. The I/O device is operable to adjust the period of the timer such that the first period approaches the predetermined time period and ad-hoc synchronization is provided between production time of the P…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.