1734-IB4 ALLEN-BRADLEY ALLENBRADLEY NEW plc USED 1734 POINT I/O IB4 Allen-Bradley 1734-IB4 Rockwell 1734-IB4 PLC 1734-IB4 Automation 1734-IB4 Industrial automation 1734-IB4 Control module 1734-IB4 I/O module 1734-IB4 Digital input 1734-IB4 AB 1734-IB4