Description

The BECKHOFF ELX3204-0090 is an intrinsically safe (Ex i) 4-channel analog input EtherCAT Terminal designed for direct connection of Resistance Temperature Detectors (RTD) located in hazardous areas classified as Zone 0/20 or 1/21. This model features integrated TwinSAFE SC (Single Channel) technology, which enables standard signals to be utilized for safety-directed tasks in safety applications up to PL d or SIL 2.

Operating on a 2-wire connection scheme, the BECKHOFF ELX3204-0090 provides 16-bit high-resolution temperature and resistance measurements. It supports a broad array of sensor types, including Pt100, Pt200, Pt500, Pt1000, Ni100, Ni120, and Ni1000, alongside general resistance measurements. Linearization of characteristic curves and digital filtering are handled directly inside the terminal to minimize processing overhead on the master controller.

Housed in a compact 12 mm mechanical form factor, the terminal connects directly to the Beckhoff EtherCAT E-bus system. To ensure compliant hazardous area isolation, field-side power contacts must be supplied using an ELX9560 intrinsically safe power supply terminal. Integrated diagnostic LEDs offer instant status monitoring for simple debugging and field commissioning.

Features

• Four differential intrinsically safe (Ex i) analog inputs for Zone 0/20 or 1/21 environments.
• TwinSAFE SC technology integration to support safety-directed system tasks up to PL d / SIL 2.
• Direct connection of Pt and Ni RTD sensors, resistance transmitters, and KT(Y) sensors.
• 16-bit analog-to-digital resolution with configurable internal conversion times.
• Integrated linearization of sensor characteristics and digital input filters.
• Electrical isolation between the field-side potential and the internal E-bus.
• Status and error diagnostic LEDs for rapid troubleshooting.

Applications

• Direct temperature monitoring of process loops in chemical, pharmaceutical, and gas processing plants.
• Intrinsically safe RTD measurement interfaces in explosive gas or dust zones.
• Safety-related process monitoring using standard RTD signals within TwinSAFE SC safety architectures.
• Distributed temperature logging in hazardous environment machine concepts.

Technical Specifications

Installation Guidelines

1. Ensure all electrical components and incoming power sources are completely de-energized before mounting or servicing.
2. Mount the terminal onto a standard 35 mm DIN rail (EN 60715) using the double slot-and-key design for correct alignment.
3. Ensure that the field-side power contacts are supplied from a verified BECKHOFF ELX9560 power supply terminal in the same segment.
4. Wire the RTD sensors using the spring-actuated terminals. Follow the standard 2-wire terminal configuration to avoid signal noise.
5. Observe all local regulations regarding physical isolation and cable separation for intrinsically safe (Ex i) electrical installations.
6. Verify configuration parameters, including sensor type, filters, and TwinSAFE SC diagnostics, in your TwinCAT project prior to system start-up.

Replacement Recommendations

When replacing a BECKHOFF ELX3204-0090, de-energize the entire terminal segment first. Document all terminal-to-sensor wiring before disconnecting the spring terminals. The replacement device must match the original configuration and safety integration level. Ensure your TwinCAT project and Safety PLC configurations are updated or verified against the new hardware revision to maintain proper TwinSAFE SC verification status.