High availability industrial automation system having primary and secondary industrial automation controllers and method of communicating information over the same

A high availability industrial automation system, the system comprising:

• a primary industrial automation controller including a first processor and a first non-transitory storage medium configured to store a first plurality of instructions, a first plurality of automation tasks, and first I/O data;
• a secondary industrial automation controller including a second processor and a second non-transitory storage medium configured to store a second plurality of instructions, a second plurality of automation tasks, and second I/O data;
• and
• a communication network connected to the primary industrial automation controller and the secondary industrial automation controller, wherein the first processor is operative to execute the first plurality of instructions to:
• receive a signal indicative to cross load less than full synchronization between the primary industrial automation controller and the secondary industrial automation controller,
• limit synchronization between the primary industrial automation controller and the secondary industrial automation controller based on the received signal, and
• cross load information from the primary industrial automation controller to the secondary industrial automation controller, the cross loading of information being less than the maximum amount of communicable information capable of being cross loaded, and wherein:
• receiving the signal indicative to cross load less than full synchronization includes the first processor being operative to execute the first plurality of instructions to receive a signal indicative to not cross load I/O synchronization information,
• limiting the synchronization between the primary industrial automation controller and the secondary industrial automation controller includes the first processor being operative to execute the first plurality of instructions to limit I/O data between the primary industrial automation controller and the secondary industrial automation controller, and
• cross loading the information from the primary industrial automation controller to the secondary industrial automation controller includes the first processor being operative to execute the first plurality of instructions to cross load automation tasks from the first industrial automation controller to the second industrial automation controller.

A primary industrial automation controller connectable to a backup industrial automation controller via a communication network, the primary industrial automation controller comprising:

• a processor module mounted on a rack having a backplane to facilitate communication at the industrial automation controller, the processor module including a processor and a non-transitory storage medium, the processor and the non-transitory storage medium configured to store a plurality of instructions, a plurality of automation tasks, and I/O data, the processor being operative to execute the plurality of instructions to
• receive a signal indicative to cross load less than full synchronization between the primary industrial automation controller and the backup industrial automation controller,
• limit synchronization between the primary industrial automation controller and the backup industrial automation controller based on the received signal, and
• cross load information from the primary industrial automation controller to the backup industrial automation controller, the cross loading of information being less than the maximum amount of communicable information capable of being cross loaded;
• and
• a first communication module mounted on the first rack, coupled to the first processor module and connectable to the first network, wherein:
• receiving the signal indicative to cross load less than full synchronization includes the processor being operative to execute the plurality of instructions to receive a signal indicative to not cross load I/O synchronization information,
• limiting the synchronization between the primary industrial automation controller and the backup industrial automation controller includes the processor being operative to execute the plurality of instructions to limit I/O data between the primary industrial automation controller and the backup industrial automation controller, and
• cross loading the information from the primary industrial automation controller to the backup industrial automation controller includes the processor being operative to execute the plurality of instructions to cross load automation tasks from the primary industrial automation controller to the backup industrial automation controller.