Number of inputs: 1 voltage or 1 current (10 A/1 A)
Signal voltage: max. 300 V AC/DC, 10 A
Internal resistance: 3 mΩ/0.2 Ω/12.5 MΩ
Conversion time: 0.5 s (1 s during measuring range switching) preset, min. 65 ms
Measured values: current, voltage
Measuring voltage: 300 mV, 3 V, 30 V, 300 V
Measuring current: 100 mA, 1 A and 10 A via high current path

Multifunction input terminal: Measures AC/DC voltage up to 300 V and current up to 10 A
High-resolution acquisition: 19-bit measurement depth for precise and detailed signal capture.
Flexible measuring ranges: Supports multiple ranges for voltage (300 mV to 300 V) and current (100 mA to 10 A).
Robust measurement design: Low internal resistance paths (3 mΩ/0.2 Ω) and 12.5 MΩ for voltage inputs ensure accuracy and minimal loss.

The Beckhoff EL3681 is a high-performance EtherCAT Terminal that functions as a universal multimeter input, providing accurate measurement of both voltage and current signals directly within an EtherCAT I/O system. With its ability to acquire AC and DC voltages up to 300 V and currents up to 10 A, it offers engineers a versatile and compact tool for monitoring electrical parameters in industrial automation environments.

The terminal supports a single input channel that can be configured for voltage or current measurement. For voltage, the EL3681 offers measuring ranges of 300 mV, 3 V, 30 V, and up to 300 V AC/DC, making it suitable for both low-level and high-voltage monitoring tasks. For current measurement, it supports ranges of 100 mA and 1 A, as well as a dedicated high-current path rated for up to 10 A. This flexibility allows it to serve in applications ranging from precision sensor measurement to monitoring the output of power circuits.

Resolution is a defining strength of the EL3681, with 19-bit measurement depth providing exceptional accuracy and fine granularity across all ranges. This ensures reliable acquisition of both small signal variations and high-level measurements, which is particularly critical in applications such as power monitoring, energy management, and test automation.

The terminal’s internal resistance is optimised for accuracy and minimal impact on the measured circuit. For high-current measurement, the resistance is as low as 3 mΩ, while the standard current path is 0.2 Ω, and voltage measurements are handled with a high 12.5 MΩ impedance. These values ensure accurate readings without introducing significant losses or affecting the source circuit.

The EL3681 has a default conversion time of 0.5 seconds, with 1 second required during range switching. For faster applications, the conversion time can be configured down to a minimum of 65 ms, offering flexibility to balance measurement speed and accuracy. This makes it suitable for both steady-state monitoring and moderately dynamic measurement tasks.

As part of Beckhoff’s EtherCAT I/O system, the EL3681 integrates seamlessly with other terminals, allowing measured values to be communicated in real time to the controller. Its compact design saves space compared to traditional standalone measurement instruments, enabling direct embedding of measurement functions into distributed automation systems.

Applications for the EL3681 include monitoring supply voltages in machines, measuring power consumption, validating control signals, or performing diagnostics on electrical installations. It is also well suited to laboratory and test environments, where precision multimeter functionality is required in a modular and networked format.

In summary, the Beckhoff EL3681 is a flexible and precise analog input terminal that combines voltage and current measurement in one compact unit. With ranges up to 300 V and 10 A, 19-bit resolution, configurable conversion times, and seamless EtherCAT integration, it delivers multimeter-grade performance for industrial and test automation. The EL3681 ensures engineers can monitor and manage electrical parameters with accuracy, efficiency, and reliability directly within their control systems.