SIEMENS · SIMATIC S7-300 · SM 322 6ES7322-1HH01-0AA0 Digital output module with 16 relay outputs, electrically isolated in groups of 8, for switching AC/DC loads within the specified operating range of the SIMATIC S7-300 system. Module Context Relay switching in an S7-300 installation The module is specified for switching direct- and alternating-current loads. Siemens documentation lists applications including solenoid valves, contactors, motor starters, small motors and