Allen-Bradley 1756-ENET Brand Introduction Allen-Bradley 1756-ENET is the first-generation EtherNet/IP communication module for Rockwell ControlLogix PLC rack system. It specializes in EtherNet/IP CIP network communication, supporting implicit real-time I/O exchange and explicit message communication, connecting HMI, remote I/O, inverters and other EtherNet/IP nodes.