PLCs, Power Supplies & Others

Technical Overview

The EH1*A operates as a versatile input module for Yokogawa CENTUM VP and CS 3000 control systems. This module accepts analog signals from field transmitters and converts them into digital values for processing. Industrial facilities depend on this input module for accurate measurement acquisition in critical process applications. The EH1*A offers multiple input types to accommodate various sensor technologies and signal ranges.

Key Specifications

Input Signal Handling and Configuration

The EH1*A supports both current and voltage input types for maximum application flexibility. Operators can configure each channel independently using the engineering software for 4–20 mA or 0–10 V DC ranges. The module’s 16-bit resolution ensures precise signal conversion with minimal quantization error. For current inputs, the module provides a built-in 250 Ω burden resistor. For voltage inputs, the EH1*A presents a high impedance of at least 1 MΩ to avoid signal loading.

Accuracy and Environmental Performance

This input module delivers an impressive accuracy of ±0.1% of span under laboratory conditions. Temperature drift remains limited to ±50 ppm per °C across the operating range. Consequently, the EH1*A maintains stable performance even in fluctuating plant environments. The module operates reliably within temperatures of -10°C to 55°C without compromising measurement integrity. With 500 V AC isolation between input channels and system logic, the module ensures safe operation and noise immunity.

Power and Electrical Characteristics

The EH1*A accepts a nominal 24 V DC supply and operates within a 20 to 30 V DC input range. Typical current consumption sits at 120 mA for the 8-channel variant, while the 16-channel version draws slightly more. Each channel updates at a rate of 100 ms, providing timely data for control loop execution. The module consumes minimal power, which reduces internal heating and enhances long-term reliability.

Mechanical Design and Installation

The EH1*A comes in a compact DIN-rail mountable enclosure with dimensions of 130 mm × 50 mm × 100 mm. Its lightweight construction of 0.35 kg simplifies handling and mounting within crowded control cabinets. The module features removable screw-type terminal blocks for easy wiring and maintenance. Each terminal accepts wire gauges from 0.2 mm² to 2.5 mm² (24 to 14 AWG). Installers appreciate the clear terminal labeling that simplifies field wiring and reduces installation errors.

System Integration and Compatibility

The EH1*A integrates seamlessly with Yokogawa CENTUM VP and CS 3000 distributed control systems. This module interfaces with the ESB bus through a coupler module for high-speed data transfer. Plant engineers can configure the module’s input parameters using the system engineering tools. The EH1*A also supports hot-swap replacement, allowing module exchange without system shutdown. Consequently, production downtime remains minimal during maintenance activities.

Practical Applications

The EH1*A serves diverse process industries including chemical, petrochemical, and pharmaceutical sectors. This input module excels in applications requiring accurate measurement of pressure, temperature, flow, and level. Its multiple input types allow connection to various field instruments without additional signal conditioners. The module’s update rate of 100 ms suits both fast-responding loops and slower thermal processes.

Operational Guidance

Mount the EH1*A securely on a DIN rail within the system cabinet. Connect field instrument wires to the corresponding terminal positions on the removable connector. Configure each channel’s input type and range using the system configuration software. Verify proper signal readings through the operator workstation before placing the loop in service. The module requires no periodic calibration, reducing routine maintenance demands. Monitor the status LED for power and communication health indicators.

Details