Product Overview

The ABB DSAI130DK01 with order code 3BSE020828R1 is a single-channel isolated temperature input module from the ABB S800 I O series, designed for integration into the Freelance and AC 800M distributed control system families. This module is specifically engineered to interface with resistance temperature detectors, providing high-precision direct temperature measurement for a single critical point. The DK suffix is key, indicating it is configured for RTD input with a specific wiring mode, while the 01 denotes a particular variant, likely specifying the RTD type and wiring configuration. The module converts the small resistance change of the RTD sensor into a high-resolution digital temperature value for the control system.

This module exemplifies the S800 series focus on high-accuracy single-channel measurement for critical loops. It features channel-to-system isolation, which is crucial for rejecting electrical noise and preventing ground loops that could severely impact the low-resistance measurement of RTDs. The DSAI130DK01 is mounted on a dedicated S800 terminal base unit specifically designed to support the 2-, 3-, or 4-wire connection required for RTDs, often including features for lead resistance compensation especially important for 3-wire connections. It is the preferred choice for applications where temperature is a key process or safety variable requiring the highest measurement integrity.

Technical Specifications

RTD Measurement Principle

The DSAI130DK01 employs the constant current excitation method for RTD temperature measurement. The module generates a precise low-level constant current, typically 0.5 mA or 1 mA, which is passed through the RTD sensor. The voltage drop across the RTD is then measured with high precision. Since the resistance of the RTD changes predictably with temperature for platinum sensors this relationship follows a defined characteristic, the module can calculate the temperature with high accuracy. The low excitation current is essential to minimize self-heating of the RTD sensor, which could otherwise introduce measurement errors. Self-heating is the phenomenon where the current passing through the sensor generates heat within the sensor itself, raising its temperature above the true process temperature. The low excitation current used in the DSAI130DK01 ensures that self-heating effects are negligible for most industrial RTD sensors.

The module supports 2-, 3-, and 4-wire RTD connections. The 2-wire connection is the simplest but does not compensate for lead wire resistance, making it suitable only for applications where lead wire resistance is negligible or where the sensor is located very close to the module. The 3-wire connection is the most common configuration for industrial RTDs. The DSAI130DK01 provides automatic lead resistance compensation for 3-wire connections, measuring the resistance of the lead wires and subtracting it from the total measured resistance to obtain the true sensor resistance. The 4-wire connection provides the highest accuracy by using separate current-carrying and voltage-sensing leads, eliminating the effect of lead wire resistance entirely.

Isolation and Noise Immunity

The DSAI130DK01 features channel-to-system isolation, which provides galvanic separation between the RTD input channel and the rest of the S800 I O system. This isolation is critical for several reasons. It prevents ground loops, which occur when multiple grounded devices are connected together, causing unwanted current to flow through the ground path and introducing measurement errors. It rejects electrical noise, isolating the sensitive RTD measurement circuit from noise generated by other I O modules, power supplies, and field wiring. It provides protection, limiting the voltage that can be applied to the module in the event of a wiring fault or transient surge. The high accuracy of the DSAI130DK01 makes it suitable for applications with demanding temperature measurement requirements, including critical process control loops where temperature measurement directly affects product quality or safety, laboratory and test stand applications requiring traceable temperature measurement, and applications with long lead wire runs where noise pickup could otherwise compromise measurement accuracy.

Key Features and Benefits

Applications

The ABB DSAI130DK01 is used in applications requiring high-accuracy single-channel temperature measurement. Typical applications include critical temperature control loops in chemical and petrochemical processes where product quality depends on precise temperature regulation, pharmaceutical manufacturing requiring validated temperature measurement for batch processing, power generation including turbine inlet temperature monitoring and boiler temperature measurement, food and beverage processing for cooking pasteurization and fermentation temperature control, and laboratory and test stand applications requiring traceable temperature measurement for research and development.

Installation and Environmental Specifications

The DSAI130DK01 is designed for installation in industrial control cabinets and panels. The module mounts on a dedicated S800 terminal base unit, which provides the physical connection points for RTD field wiring. The base unit must be installed on a standard DIN rail conforming to IEC 60715. Ambient temperature must be maintained within the -25°C to +70°C operating range for reliable operation. The module should be protected from direct moisture exposure and excessive dust accumulation within the IP20 protection rating. Proper shielding and grounding practices for RTD wiring should be followed to minimize electromagnetic interference and ensure measurement accuracy.

Standards Compliance

The DSAI130DK01 complies with relevant IEC standards for industrial measurement and control equipment, including IEC 61131-2 for programmable controllers and IEC 61000 for electromagnetic compatibility.