The Allen-Bradley 1747-ASB is a SLC 500 I/O Adapter Module. This I/O Adapter Module has a Universal Remote I/O Adapter Communication Port and which supports Communication Rate of 57.6, 115 or 230 kilobits/second.
The 1747-L30A is a controller module for the SLC 500 Modular Hardware by Allen-Bradley. It comes with 1K Instruction Capacity with Eighteen (18) 120 Volts AC and Twelve (12) AC/DC Relay. It has an input power rating of 120/240 Volts AC with built-in communication interfaces of DH485 communication port