Siemens 6ES7 322 IHF01 0AA0 Relay Output Module

Siemens SIMATIC S7-300 SM 322 DO 8xRel (6ES7322-1HF01-0AA0) is an eight-channel relay output module designed for the S7-300 controller family, delivering isolated relay contacts that switch external loads up to 2 A per channel. Each of the eight outputs can switch either AC loads up to 230 V or DC loads up to 24 V, enabling reliable control of actuators, solenoids, contactors, signaling devices, and other field devices in automation cabinets. The SM 322 uses a standard 1×20-pole interface to connect to the S7-300 backplane and is intended for mounting in the S7-300 rack; its channels are galvanically isolated from one another and are grouped in two to facilitate power distribution and wiring. As a relay-based output module, it provides dry-contact switching with no direct PLC current path for the loads, offering robust operation in environments where switching of higher-power devices is required. The module is part of Siemens' SIMATIC S7-300 module lineup and integrates with existing CPUs, wiring schemes, and programming workflows for scalable automation solutions.