ABB Pluto S20 V2 CFS Programmable Safety Controller (2TLA020070R4700)

The ABB Pluto S20 V2 CFS is a compact, configurable safety PLC designed for industrial machine safety applications. It replaces multiple safety relays by integrating logic functions such as AND, OR, timers, and muting. The unit features 8 safety inputs (24 V DC, OSSD compatible) and 4 safety transistor outputs (PNP, 2 A each). It is certified for SIL 3 (IEC 61508) and PL e (ISO 13849-1), making it suitable for Category 4 safety systems. The Pluto S20 V2 CFS is programmed using ABB's free Pluto Manager software (graphical function block programming). The controller can also communicate with standard PLCs via the built‑in Modbus RTU (RS‑485) or optional PROFIBUS gateway.

Technical Specifications

Functional Description

The Pluto S20 V2 CFS executes a safety‑rated logic program created using function blocks in Pluto Manager. The software includes pre‑certified safety blocks for emergency stop monitoring (dual‑channel), light curtain integration with OSSD pulsing, muting function (for material feeding), two‑hand control (type III C), and delay timers. The program is downloaded via a USB connection (mini‑B port) to the controller. The inputs accept both standard 24V DC sensors and OSSD pulse outputs from safety light curtains. The controller monitors cross‑circuits between channels and detects wire breaks. Outputs are short‑circuit proof and feature cross‑fault detection. The device can be used stand‑alone or networked with additional Pluto units via the Pluto bus (RS‑485).

Diagnostics and Status Indication

The front panel provides:

• Green LED: Power / Run

• Red LED: Fault (internal or wiring)

• 8 yellow LEDs: Input status (each channel)

• 4 green LEDs: Output status

• 8 diagnostic LEDs: For test outputs and communication

The Pluto Manager software offers online monitoring of inputs, outputs, and internal variables, plus a simulation mode. The controller stores the last 50 error events with timestamps. Diagnostic messages include short‑circuit detection, cross‑circuit detection, channel imbalance, and wire break.

Safety Standards

The Pluto S20 V2 CFS is certified by TÜV SÜD and meets: IEC 61508 (SIL 3), ISO 13849-1 (PL e / Category 4), IEC 62061 (SIL CL 3), EN 954-1 (Category 4). It also complies with machine safety standards: EN 60204‑1 (electrical equipment of machines), EN 60947‑5‑1 (positive‑opening contacts), and EN 61496‑1 (sensing devices).

Applications

The Pluto S20 V2 CFS is used for emergency stop monitoring on packaging lines, light curtain integration on robotic workcells, two‑hand control on hydraulic presses, safety gate monitoring with guard locking, and muting for automated material feeding. It replaces up to 10 standard safety relays, reducing panel space and wiring complexity.

Installation Overview

Mount the controller on a DIN rail. Connect the 24V DC supply to terminals “+” and “-”. Connect dual‑channel emergency stop buttons to inputs I1/I2 (channel 1) and I3/I4 (channel 2). Connect the safety outputs to contactor coils. The test outputs can power sensors and light curtains. Use separate cables for each channel to maintain cross‑circuit detection. After wiring, download the configuration via USB. Test all safety functions before commissioning.

Conclusion

The ABB Pluto S20 V2 CFS offers a flexible, easy‑to‑program safety PLC with high integrity and compact size, making it ideal for machine safety upgrades and new installations.