Allen-Bradley 1768-L43S Compact GuardLogix Controller – 2MB Safety Memory By wayne No Comments on Allen-Bradley 1768-L43S Compact GuardLogix Controller – 2MB Safety Memory 2 Min Read Expert evaluation of the 1768-L43S safety controller with 2MB standard memory and 0.5MB safety memory. Ideal for EtherNet/IP and ControlNet systems.