Siemens simatic s7 200 add on modules siemens 6es7223 1hf22 0xa0 this digital io module is from the simatic s7 200 modular range the unit has 4x digital inputs and 4x digital relay outputs with a load voltage of 24v dc and 24 to 230v ac siemens 6es7223 1hf22 0xa0 sps add on module em 223