Siemens 6ES7223-1PL21-0XA0 EM 223, 16DI/16DO Relay

The Siemens 6ES7223-1PL21-0XA0 is a SIMATIC S7-200 EM 223 expansion module adding 16 digital inputs (24 V DC, sink/source) and 16 relay outputs rated 2 A per point. This mix of high-side input flexibility and isolated relay switching is what you need when the base CPU I/O is used up and you're running mixed DC sensors and AC or high-current loads off the same rack. It is designed exclusively for S7-22X CPUs — the EM 223 slots directly onto the CPU's expansion bus; no extra addressing or separate power supply needed. The 16 relay outputs give you galvanic isolation and a 2 A continuous contact rating, enough for pilot lights, contactor coils, or small valves without an interposing relay.