`Hot' back-up system for PLC controllers
15 Jan 2000
A new `slide-in' card from Rockwell Automation provides hot back-up for its Allen-Bradley PLC-5 family of controllers.
According to product manager Mark Daniels, `in refining, mining, chemical and related industries, redundancy is a critical requirement for control systems. Our solution fulfils this need by combining the traditional reliability of the PLC-5 with the most up-to-date industrial networking technology.'
The back-up system requires two processors fitted with the slide-in card, programmed identically and connected to the same I/Os. These processors then communicate using a ControlNet back-up module via the `producer/consumer' network, which allows all nodes on the network to simultaneously access the same data from a single source.
