6ES7422-7BL00-0AB0 - Digital Output Module - SIEMENS

SIMATIC S7-400 SM 422, 32 x 24 V DC digital output module, fast, safe switching

Designed for critical automation infrastructures, the SIEMENS SIMATIC S7-400 SM 422 module delivers 32 digital 24 V DC outputs for precise control of on/off actuators. It is aimed at maintenance managers, automation engineers and integrators seeking high I/O density, maximum availability and native integration into the S7-400 ecosystem. Galvanic isolation strictly separates control and power circuits, reducing fault propagation risk and improving downstream equipment safety. The typical response time of 0.15 ms ensures deterministic switching for high-speed cycles. Integrated diagnostics, available directly in the PLC logic and via status LEDs, speed up fault identification and help reduce MTTR. Combining switching speed, robustness and diagnostics, this module is a reliable standard for S7-400 digital I/O.

Optimised productivity, safety and maintenance

• Deterministic switching – A 0.15 ms response time stabilises fast sequences, reduces bottlenecks and makes cycle times more reliable.
• Galvanic isolation – Strict separation of control and power limits disturbance propagation and protects downstream actuators.
• High I/O density – 32 digital outputs on a single module reduce cabinet space and simplify wiring.
• Integrated diagnostics – Visibility of output status and faults accelerates troubleshooting and enables proactive maintenance.
• S7-400 integration – Native compatibility with the SIMATIC S7-400 platform for streamlined commissioning and long-term operation.

Robust architecture and controlled features

The SM 422 supplies 32 on/off outputs at 24 V DC, suitable for driving typical continuous loads in industrial automation. Each output supports up to 0.5 A, covering common needs such as solenoid valves, interface-driven contactors, indicator lights and signalling devices. Galvanic isolation provides a proven barrier between logic and power, helping protect equipment and stabilise measurements. The fast switching speed of 0.15 ms supports sustained cycle rates while ensuring temporal repeatability of signals. Integrated diagnostics deliver status information directly usable by the PLC, enabling monitoring and alarm routines without additional hardware. Built to SIEMENS quality standards, this module fits naturally into an S7-400 rack to form a durable, streamlined digital I/O chain.

Industrial applications and use cases

The SM 422 is suitable for assembly lines, conveyors, packaging machines, intralogistics, discrete processes and production skids. It reliably drives solenoid valves, pneumatic distributors, indicator lights, alarms and simple control elements. Maintenance teams and integrators use it to increase I/O density, optimise availability and structure diagnostics for integration into CMMS and alarm routines. S7-400 compatibility ensures frictionless integration into existing or upgraded architectures.

Technical differentiation and reassurance

The combination of effective galvanic isolation, short response time and integrated diagnostics positions the SM 422 as a stable reference for S7-400 digital I/O. The proven reliability of the SIEMENS platform, validated across a wide installed base, builds confidence during modernisations or line extensions. By choosing Standard Exchange Industry, you benefit from responsive logistics, standard-exchange, new or refurbished solutions, and a repair service. Services come with warranties ranging from 6 to 24 months depending on the option, securing your investment and controlling total cost of ownership.

Need fast availability to restart a line or plan a controlled refresh of your S7-400 digital I/O? Contact our team for an immediate quote, dispatch within 24 to 72 h depending on stock, and the technical support required for commissioning without schedule delays.