Description
CODESYS Redundancy SL makes it possible to run one and the same IEC 61131-3 application on two independent soft PLC systems at the same time. If a control fails, the passive control is activated. The function enables the mutual monitoring and synchronization of two controllers.
The redundant cross-connection between the two controllers is implemented using a TCP/UDP-based protocol. The active controller controls the I/O system, while the passive controller monitors the active controller and synchronizes itself with it. When the redundant system is started up, the first PLC started goes into the “standalone” state until the second PLC is started and synchronized. Then the first changes to the active state, the second to the passive state (standby). If a control fails, there is an automatic switchover.
A manual switchover can be initiated via a function interface. The boot application and the memory are updated automatically. IEC timers are synchronized in each task cycle.
