Beckhoff KS2701 Bus Terminal: Relay Output

Product Overview

The Beckhoff KS2701 (KS2701) is a high-performance Bus Terminal designed for industrial switching applications. Featuring a single-channel relay output (make contact), it provides seamless integration for controlling ohmic and inductive loads up to 230 V AC/DC. Its flexible connection technology supports 2-, 3-, and 4-wire configurations, making it a versatile choice for a wide range of automation tasks. By offering 2500 V AC electrical isolation between the field side and the internal K-bus, the KS2701 ensures robust protection of your PLC and communication infrastructure against voltage transients.

Technical Configuration

Designed for the modular Beckhoff Bus Terminal system, the KS2701 is housed in a compact, pluggable polycarbonate enclosure. It is engineered to handle substantial switching demands, featuring a steady-state current rating of 3 A and the capacity to handle peak currents of up to 50 A for short durations (100 ms). The terminal requires no manual address or configuration settings, allowing for "plug-and-play" deployment. With its integrated surge voltage protection (starting at 400 V AC), this terminal is exceptionally well-suited for switching inductive loads, such as contactor coils or small solenoid valves, while maintaining precise 2–4 ms switch-off times.

Technical Specifications

FAQs

Why is surge voltage protection important for this terminal?

When switching inductive loads (like solenoids or large contactors), the collapsing magnetic field generates a high-voltage transient (back EMF) that can damage electronic components. The integrated surge protection (starting at 400 V) suppresses these spikes, significantly extending the relay's service life.

Can I use this terminal for low-voltage signal switching?

While the KS2701 is robust enough for 3 A loads, the gold-free contacts are optimized for general-purpose switching. For extremely low-current, low-voltage signal applications (e.g., < 10 mA, < 5 V), consider using a terminal with gold-plated contacts to ensure reliable signal continuity.

Does this terminal require configuration in TwinCAT?

No, the KS2701 is a self-configuring device. Once connected to the K-bus, the system detects it automatically, occupying 2 bits in the process image. No manual addressing is required.

What is the recommended fuse for this terminal?

To protect the relay contacts from welding during a short circuit, you should install a fast-acting fuse rated at ≤ 10 A in series with the load.

Installation Guidelines and Best Practices

• Wiring: The KS2701 uses spring-actuated terminals. Use a screwdriver to actuate the spring, insert the wire (0.08–1.5 mm²), and ensure a stripping length of 9–10 mm. This connection method is highly vibration-resistant and requires no re-tightening over time.
• Thermal Management: With a steady load of 3 A, the terminal remains efficient; however, when mounting several relay terminals side-by-side, be mindful of cumulative heating. Ensure the control cabinet is ventilated to keep the ambient temperature within the 0–55 °C range.
• Grounding & Isolation: The 2500 V AC isolation is critical for safety. Ensure your field wiring for the 230 V circuit is kept physically separate from low-voltage (24 V DC) sensor and communication wiring to prevent capacitive coupling and potential safety hazards.
• Mounting: The terminal snaps directly onto 35 mm DIN rails (EN 60715). Use the integrated lock mechanism to secure the terminal in place, especially in high-vibration environments like industrial presses or high-speed conveyors.