Product Description

The FBM214 (RH927AH) is a high-performance 8-channel HART analog input module designed for the Foxboro I/A Series and Foxboro Evo distributed control systems. It enables simultaneous acquisition of standard 4–20 mA process variables and HART digital communication data from smart field devices.

Unlike conventional analog input modules, the FBM214 integrates a pulse-width modulated (PWM) signal path that supports bidirectional HART communication superimposed on the analog current loop. This allows remote device configuration, calibration, and diagnostics without interrupting the process signal, improving system availability and maintenance efficiency.

Each input channel is fully galvanically isolated to ensure high signal integrity in electrically noisy industrial environments. The module supports HART-enabled pressure, temperature, and flow transmitters commonly used in critical process applications.

Technical Specifications

Module Type: 8-Channel Isolated HART Analog Input
Part Number: RH927AH
Input Signal Range: 4–20 mA DC with HART digital overlay
Input Impedance: 250 Ω nominal
A/D Resolution: Minimum 15-bit
Update Rate: 100 ms for all 8 channels
Channel Isolation: Galvanic isolation from ground and logic circuitry
Loop Power: 24 V DC provided to each channel
Power Consumption: Maximum 2.5 W at 24 V DC
Operating Temperature: −20 to +70 °C 
Relative Humidity: 5% to 95% 
Dimensions (W × H × D): 2.2 × 12.4 × 12.6 cm
Net Weight:  0.1 kg
Baseplate Compatibility: Foxboro 200 Series high-density baseplates
Country of Origin: United States of America

Application

The FBM214 (RH927AH) is widely used in process industries where HART-enabled instrumentation and predictive maintenance are required. Typical applications include chemical processing plants, oil and gas facilities, and power generation systems, where access to secondary variables and device diagnostics improves reliability, asset management, and maintenance planning.