Beckhoff EL2911-2200 TwinSAFE Logic Terminal for EtherCAT

The Beckhoff EL2911-2200 is a TwinSAFE logic terminal that combines safety logic execution with 8 fail-safe digital outputs in a single EtherCAT slave device. It is part of the Beckhoff EL series I/O terminals and allows distributed safety control without a dedicated safety CPU. The terminal meets SIL 3 (IEC 61508) and PL e (ISO 13849-1) requirements, making it suitable for machinery safety applications including emergency stops, light curtains, and two-hand controls.

Safety Outputs

The EL2911-2200 provides 8 safety-rated digital outputs (O0 to O7), each capable of switching 24 VDC at 0.5 A (resistive load). Outputs are short-circuit protected and cross-circuit monitored. Each channel has two redundant internal switches (p-channel and n-channel) to achieve fail-safety. The outputs support both high-side and low-side switching (PNP type). The maximum total current per module is 4 A (derating above 40°C). Output response time:<10 ms (from logic evaluation to output state change).

Safety Logic Engine

Integrated TwinSAFE logic engine can execute up to 32 safety connections (e.g., safety chains, muting, bypass). The terminal stores the safety application in its non-volatile memory (16 KB). Logic is programmed using TwinSAFE Editor within TwinCAT 3. Supported safety functions: emergency stop, guard monitoring, two-hand control (type III), muting, timer functions (on-delay/off-delay), and cross-circuit detection. The terminal has a failsafe microcontroller (dual-core lockstep) with a cycle time down to 5 ms.

EtherCAT Communication

The terminal connects to the EtherCAT network via the standard E-bus. It supports distributed clocks (DC) for synchronized data exchange with other safety terminals (EL19xx series). The safety protocol is TwinSAFE (FSoE – FailSafe over EtherCAT) according to IEC 61784-3-12. Up to 128 TwinSAFE devices can be networked. The terminal includes two M12 connectors (on request) or standard Beckhoff cage-clamp terminals.

Diagnostics and Status LEDs

LED indicators: RUN (green, EtherCAT state), ERR (red, communication error), SAFE (green, safety logic ok), OUT (yellow per channel). Additionally, a 7-segment display shows internal error codes and safety ID. The terminal logs all safety events (timestamped) in an internal buffer (1000 entries). Diagnostic objects are accessible via TwinCAT System Manager.

Power Supply

The EL2911-2200 derives its logic power from the E-bus (24 V from power supply terminal). The output power (for field devices) must be supplied separately via the terminal’s power contacts (US = 24 VDC, 0 V). The module consumes 120 mA from the E-bus and 20 mA from the field supply per active output (plus load). The power supply range is 20.4 to 28.8 VDC with galvanic isolation between E-bus and outputs (1500 V).

Environmental Specifications

Operating temperature: -25°C to +60°C (extended range). Storage: -40°C to +85°C. Humidity: 95% non-condensing. Vibration: 5 g (10–500 Hz), shock 30 g. Protection class: IP20. Dimensions: 24 mm width x 100 mm height x 68 mm depth (typical Beckhoff terminal housing). Weight: 100 g. The terminal is UL listed (UL 61010-1) and CE certified.

Configuration and Software

Configuration requires TwinCAT 3 (Build 4024 or later) with the TwinSAFE license (TF5800). The safety project is created offline and then downloaded to the terminal via the EtherCAT bus. The terminal supports “online change” of safety parameters without stopping the safety CPU. Password protection prevents unauthorized modifications. All safety parameters are CRC checked.

Safety Certifications

• SIL 3 (IEC 61508:2010).

• PL e (ISO 13849-1:2015).

• Category 4 (EN 954-1).

• TÜV certified (certificate no. 968/EL 2911).

The terminal also meets EN 62061 and IEC 61800-5-2 for drive safety.

Applications

Used in packaging machinery, robotics cells, conveyor systems, and printing presses. The 8 outputs can directly drive safety contactors (e.g., for motor braking) or signal to a safety PLC. Because it contains a logic engine, the EL2911-2200 can replace a standalone safety relay, reducing panel space.

Ordering and Accessories

Order code: EL2911-2200 (the -2200 suffix denotes TwinSAFE logic and 8 outputs). Accessories include an end cap (EL9011) for bus termination, and a power distribution terminal (EL9188). Manual: Beckhoff TwinSAFE Application Guide (AN0115). For wire connection, use 0.2–2.5 mm² (AWG 24–12).