Allen-Bradley 1785-L40B PLC-5/40 Controller 48K Memory By wayne No Comments on Allen-Bradley 1785-L40B PLC-5/40 Controller 48K Memory 3 Min Read Buy the Allen-Bradley 1785-L40B PLC-5/40 controller with 48K words of memory. It supports 2048 I/O points and four DH+/RIO networks for your automation needs.