The Siemens 6ES7223-1EF00-0XA0 is a SIMATIC S7-200 digital I/O expansion module, type EM 223, providing 4 opto-isolated inputs and 4 outputs rated for 120 VAC operation. It is designed exclusively for use with S7-21X series CPUs. This module adds mixed I/O capacity to a compact S7-200 rack without requiring a separate power supply; it draws its backplane power from the CPU. The 120 VAC input threshold means it interfaces directly with line-voltage sensors or limit switches, eliminating the need for an interposing relay in many panel layouts.
Lifecycle reality — being discontinued
For a BOM line that depends on this exact module, the practical path is to source remaining new stock through independent distribution channels while it is still available.