OMRON DRT2-AD04H DeviceNet Analog Input Terminal: Precision Remote Data Acquisition

The OMRON DRT2-AD04H is a smart analog input slave unit designed for DeviceNet networks. Part of the DRT2 series, this terminal provides 4 isolated analog input channels, each configurable for voltage or current signals. It enables high-precision measurement and remote data collection in distributed control systems, reducing wiring costs and improving noise immunity. The DRT2-AD04H is ideal for applications requiring real-time monitoring of temperature, pressure, flow, or position sensors.

Technical Specifications and Input Ranges

Each of the 4 channels supports software-selectable input ranges: ±10V, 0-10V, 0-5V, 1-5V, 0-20mA, and 4-20mA. The resolution is 1/4000 (12-bit) for all ranges, ensuring accurate conversion. The terminal offers a conversion speed of 1 ms per channel (max. 4 ms for all channels) with simultaneous sampling capability. Input impedance is 1 MΩ for voltage inputs and 250 Ω for current inputs. The DRT2-AD04H also provides 500 VAC isolation between input channels and the DeviceNet bus, as well as between channels themselves.

DeviceNet Integration and Configuration

The DRT2-AD04H communicates via the DeviceNet protocol, supporting both polled and change-of-state (COS) I/O messaging. The unit’s node address and baud rate (125k, 250k, 500k bps) are set via rotary switches. Configuration is performed using OMRON’s CX-Integrator or any standard DeviceNet master. The terminal provides explicit messaging for setting input range, scaling, alarm thresholds, and averaging filters. It also features a built-in LED indicator for network status, module power, and per-channel input overrange detection.

Advanced Diagnostics and Smart Functions

Unlike basic analog terminals, the DRT2-AD04H includes intelligent functions such as wire break detection (for 4-20mA loops), peak/bottom hold, and digital filtering (moving average up to 255 samples). Each channel can be configured with high/low alarm limits that trigger status bits in the input data. The unit also supports offset/gain adjustment for field calibration. The diagnostic information is accessible via the DeviceNet master, enabling predictive maintenance and rapid troubleshooting.

Physical and Environmental Characteristics

The DRT2-AD04H features a compact, DIN-rail mountable housing measuring 120mm (H) x 50mm (W) x 75mm (D). It is rated IP20 for protection against solid objects. Operating temperature range is -10°C to 55°C, with storage from -25°C to 65°C. The terminal accepts solid or stranded wires (0.2 to 2.5 mm²) via removable screw terminal blocks. It meets CE, UL508, and CSA standards, and is compliant with the DeviceNet specification (Volume II).

Typical Applications

The DRT2-AD04H is commonly used in process automation, packaging lines, material handling, and environmental monitoring. For example, it can collect analog signals from multiple pressure transducers located on a remote conveyor, sending data to a central PLC via DeviceNet. It is also suitable for retrofit projects where existing analog sensors need to be integrated into a DeviceNet network without replacing the sensors. The unit’s isolation ensures signal integrity in electrically noisy environments such as welding cells or inverter-driven machinery.

Installation and Maintenance

Installation involves connecting the DeviceNet cable (5-pin open-style connector) and wiring analog inputs to the terminal block. The unit derives power from the DeviceNet bus, no separate power supply required. Periodic inspection includes verifying terminal tightness and checking LED status. OMRON provides a user manual (W347) and EDS files for easy integration with third-party DeviceNet scanners. With its robust design and flexible configuration, the DRT2-AD04H remains a trusted choice for distributed analog I/O applications.