The X20 control systems include redundancy features. The controllers can be reconfigured at any time with features that reduce downtime using the Automation Studio software, eliminating the need for specialized redundancy controllers. Engineering effort is reduced to declaring the PLC a redundant unit and configuring communication parameters or failure criteria.
One controller provides active control while a second controller runs in the background in standby mode. All network functions are monitored continuously so that when the time comes, the backup controller can quickly take over all of the active PLC functions. Whichever controller becomes active always uses the same IP address as its predecessor. The switching time of the system is two task cycles – so all of this takes place in a matter of a few milliseconds.
The redundancy system is powered by the real-time Ethernet Powerlink communication protocol. An independent high-speed fiber optic redundancy link continually synchronizes all important data – the I/O image, for example – between the active and inactive controllers.
B&R Industrial Automation Corp.
Filed Under: Design World articles
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