ABB Pluto S20 V2 CFS Safety PLC: Configurable Safety Controller for Machine Protection

The ABB Pluto S20 V2 CFS (article number 2TLA020070R4700) 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 (expandable via Pluto bus) and 4 safety outputs, each capable of switching up to 2A at 24 VDC. It is certified for SIL3 (IEC 61508) and PLe (ISO 13849-1), suitable for Category 4 safety systems. The Pluto S20 V2 CFS is programmed using ABB’s Pluto Manager software (free download).

Input and Output Specifications

The eight safety inputs accept dual-channel signals from emergency stop buttons, safety door switches, light curtains, and two-hand control devices. Inputs are compatible with OSSD (pulse test) outputs from safety sensors. The four safety outputs are transistor-based (solid state) with short-circuit protection and cross-circuit monitoring. Each output provides 2A continuous current, and the total output current is limited to 4A per module. Additionally, there are 4 test outputs (pulse sources) for wiring diagnostics.

Logic and Programming

The Pluto S20 V2 CFS contains a microprocessor that executes a safety-rated logic program. Using the Pluto Manager software (Windows-based), engineers create function block diagrams with pre-certified safety blocks (e.g., emergency stop monitoring, muting, bypass, timer). The software includes a simulator for offline testing. The program is transferred via a USB cable (type mini-B). The controller stores the program in non-volatile flash memory. Up to 64 function blocks can be used, and the total cycle time is typically under 10 ms. The device also supports password protection to prevent unauthorized changes.

Diagnostics and Status Indication

The front panel features LEDs: green (power/run), red (fault), and eight yellow LEDs for input status, four green LEDs for output status. The Pluto Manager software provides real-time monitoring of each input, output, and internal variable. Diagnostic information includes short-circuit detection, cross-fault detection (between two channels), and wire break detection for inputs. A non-volatile error log stores the last 50 events. The device can also send status via the optional Pluto bus to a standard PLC (using Modbus RTU over RS-485).

Mechanical and Environmental Data

The Pluto S20 V2 CFS measures 110mm (H) x 45mm (W) x 115mm (D) and mounts on 35mm DIN rail. It is rated IP20 for the enclosure. Operating temperature: -10°C to +55°C, storage -25°C to +70°C. Humidity: 5% to 95% non-condensing. Vibration: 5G (10-150 Hz). The terminal blocks are removable (plug-in type) for easy wiring. All terminals are labeled with function. The housing is made of polycarbonate (UL94 V-0).

Typical Applications

The Pluto S20 V2 CFS is used for: emergency stop monitoring on packaging machines, light curtain integration on robotic cells, two-hand control on presses, safety gate monitoring with guard locking, and muting for material feeding. Its compact size allows installation in small control cabinets. The configurable logic eliminates the need for multiple safety relays and timers, reducing wiring and troubleshooting time. It can also communicate with a standard PLC for non-safety status (e.g., machine running, guard open).

Expansion and Networking

The Pluto S20 V2 CFS can be expanded with additional Pluto S20 I/O modules (e.g., 2TLA020070R4800 for 8 inputs, or 2TLA020070R4900 for 4 outputs) via the Pluto bus (RJ12 connector). Up to 7 expansion modules can be connected, providing a total of up to 64 inputs and 32 outputs. The bus cable length is limited to 30 meters. For integration with standard PLCs, the Pluto S20 V2 CFS offers a non-safety RS-485 Modbus RTU slave interface. The safety integrity is maintained regardless of communication.

Ordering and Compliance

Order number: 2TLA020070R4700 (also referred to as Pluto S20 V2 CFS). The package includes the controller, a terminal block set, and a USB programming cable (2m). The Pluto Manager software is available for free download from ABB’s website. The unit is CE marked, TÜV certified, and compliant with Machinery Directive 2006/42/EC. For safety validation, ABB provides a safety manual with performance level calculation examples. The product has a typical lifespan of 10 years.