Pilz 312070 PSSu H PLC1 FS SN SD Fail‑safe Safety Module

The Pilz 312070 (PSSu H PLC1 FS SN SD) is a safety module for the PSSuniversal automation system. It combines a programmable fail‑safe logic controller (Safety PLC) with integrated digital I/O. The module is certified to SIL3 (IEC 61508) and PL e (ISO 13849‑1), making it suitable for safety‑critical applications such as emergency stop circuits, guard door monitoring, light curtain evaluation, and two‑hand controls. The PSSu H PLC1 operates as a head station in a PSSuniversal system, managing both safety and standard I/O modules. It features a powerful processor, onboard safety inputs and outputs, and multiple communication interfaces.

Technical Specifications

Supply voltage: 24 V DC (20.4‑28.8 V). Power consumption: 2.5 W (typical). Integrated safety inputs: 16 (24 V DC, Type 3). Integrated safety outputs: 8 (PNP transistor, 0.5 A each). Test outputs: 4 (PNP, 0.1 A). Program memory: 1 MB Flash, 256 KB RAM. Execution time: 0.2 ms per 1K logic. Communication: Ethernet (Modbus TCP, PROFINET optional), RS‑232 diagnostic port. Operating temperature: -10°C to 55°C. Storage: -25°C to 70°C. Dimensions: 120 mm × 45 mm × 110 mm. Weight: 220 g. Protection: IP20. Certifications: CE, TÜV, UL, RoHS.

Key Features

• Fail‑safe programmable safety controller for PSSuniversal

• 16 safety inputs, 8 safety outputs, 4 test outputs on‑board

• SIL3 (IEC 61508) and PL e (ISO 13849‑1) certified

• Integrated Ethernet port for programming and diagnostics

• Supports PROFINET and Modbus TCP

• Expandable with PSSuniversal I/O modules (up to 64 modules)

• Programming with Pilz PAS4000 software (FBD/LD)

• Diagnostic LEDs for all I/O and system status

Safety Functions

The module can implement safety functions including emergency stop monitoring (dual‑channel), safety gate interlocking with cross‑circuit detection, two‑hand control (type III), light curtain and safety mat evaluation, and speed monitoring (with external encoders). The integrated test outputs can be used for OSSD pulsing or cross‑circuit detection. The safety program is created using Pilz PAS4000 software, which includes certified function blocks for common safety applications. The module supports both automatic and monitored manual reset.

Integration into PSSuniversal System

The 312070 acts as the head station (master) for a PSSuniversal I/O system. It mounts on a DIN rail and communicates with up to 64 expansion modules (safety or standard I/O) via the internal system bus. The module can exchange data with a higher‑level standard PLC via Ethernet (Modbus TCP or PROFINET). It also provides diagnostics and configuration via a web server.

Programming and Configuration

Pilz PAS4000 software (versions 1.0 and higher) is used to program the safety logic using function block diagram (FBD) or ladder diagram (LD). The software includes a library of pre‑certified safety function blocks. The program is downloaded via Ethernet or the RS‑232 diagnostic port. Online monitoring and debugging are supported. The module also supports firmware updates and password protection for the safety program.

Applications

The 312070 is used in machine safety systems for industrial machinery such as packaging equipment, robotics cells, conveyor systems, printing presses, and automated assembly lines. Its integrated I/O reduces wiring and component count, making it suitable for standalone safety applications or distributed safety systems.

Installation and Wiring

Mount the module on a 35 mm DIN rail. Connect 24 V DC power to the terminals (A1, A2). Wire safety inputs (I0‑I15) to emergency stop buttons, safety switches, or light curtain OSSD outputs. Wire safety outputs (O0‑O7) to contactor coils or safety relays. Connect test outputs (T0‑T3) to devices requiring test pulses. Use shielded cables for long runs. The Ethernet port uses a standard RJ45 cable. After wiring, power up and verify that the module’s LEDs indicate normal operation (green RUN).

Diagnostics and Maintenance

LEDs: PWR (green), RUN (green), ERR (red), IN (yellow) for inputs, OUT (green) for outputs. If the ERR LED is on, check the diagnostic buffer via PAS4000. The module has no user‑serviceable parts; replace if faulty. Keep the module free from dust.

Conclusion

The Pilz 312070 PSSu H PLC1 FS SN SD safety module offers a compact, high‑integrity control solution for machine safety applications. Its integrated I/O, expandability, and SIL3/PL e certification make it a versatile choice for implementing fail‑safe logic in modern industrial machinery.