The Allen-Bradley 1769-L23E-QB1B is a CompactLogix 5370 L2 Packaged controller. It is part of the CompactLogix Programmable Automation Controller (PAC) product family which features built-in One (1) Ethernet and One (1) RS232 communication ports. It has 512KB embedded user memory and supports installation of up to Three (3) 1769 I/O modules.