Mitsubishi FX5-SF-MU4T5: Safety Extension Main Module for MELSEC iQ-F

The Mitsubishi FX5-SF-MU4T5 is a safety extension main module designed for the MELSEC iQ-F series of programmable logic controllers. By connecting this safety main module to an FX5U, FX5UC, or FX5UJ CPU module, a single system can be used to perform both general-purpose control and safety control simultaneously. This architecture eliminates the need for a dedicated safety control CPU or separate network systems to monitor safety control status, and also reduces the extensive wiring and labor required when constructing systems with safety relays.

Technical Specifications

The FX5-SF-MU4T5 provides 4 safety input points and 4 safety output points, suitable for integrating safety devices such as emergency stop switches, safety door switches, and light curtains directly into the iQ-F control system. The module features a spring clamp terminal block type, which enables tool-free wiring and reliable connections in industrial environments. An off-delay time of 0 to 5 seconds can be configured, allowing flexible timing adjustment for various safety applications.

Safety-Level Certifications

The FX5-SF-MU4T5 meets stringent safety standards including SIL3 according to IEC 61508 and SILCL3 according to IEC 62061, certifying it for use in safety-critical applications up to Performance Level e (PLe) as defined in ISO 13849-1. These certifications ensure that the module can be integrated into machine safety systems requiring the highest levels of safety integrity, such as those found in packaging machinery, robotic cells, and automated assembly lines.

System Integration Architecture

The safety extension main module connects directly to the FX5U/FX5UC/FX5UJ CPU via the internal bus, enabling the CPU to process both standard control logic and safety control logic within the same scan cycle. The safety I/O data is mapped to dedicated safety memory areas, allowing the user program to read safety input status and control safety outputs using standard programming instructions. This integrated approach simplifies system design, reduces hardware costs, and shortens engineering time compared to standalone safety relay systems or dedicated safety PLC architectures. Additional safety input expansion modules, such as the FX5-SF-8DI4, can be added to increase the number of safety input points for larger safety applications.

Spring Clamp Terminal Block Design

The spring clamp terminal block eliminates the need for screw tightening, significantly reducing installation time and preventing miswiring accidents associated with loose screws. The terminal accept solid or stranded wires and provide reliable contact under vibration common in industrial machinery. The terminal block is removable, enabling efficient module replacement without disturbing field wiring.

Typical Applications

The FX5-SF-MU4T5 is deployed in safety-critical automation applications including emergency stop monitoring in packaging machinery, safety door interlock systems on robotic cells, light curtain integration on automated assembly lines, two-hand control systems for hydraulic presses, and muting applications for material feeding conveyors. The integrated safety approach simplifies system architecture by handling both standard machine control and safety monitoring on a single CPU platform.