Overview
The FBM204 is a versatile analog I/O module equipped with four 20 mA DC analog input channels
and four 20 mA DC analog output channels, designed to bridge field-level sensor signals and
industrial control systems. Each input channel is capable of accepting signals from 4–20 mA
transmitters or self-powered 20 mA sources, while each output channel can drive external loads and
deliver precise 0–20 mA output signals. Notably, all input and output channels feature galvanic
isolation from one another and from ground, ensuring signal integrity and protection against
electrical interference or cross-channel faults.
Beyond basic signal transmission, the FBM204 handles the necessary signal conversion to interface
field sensor electrical signals with an optionally redundant fieldbus. It runs a dedicated Analog I/O
application program that supports per-channel configurable parameters, including conversion time,
fail-safe behavior (either hold or fallback modes), and analog output fail-safe fallback data. For
enhanced control capabilities, the module can alternatively execute a distributed PIDA (DPIDA)
application program, enabling fast, localized control loops to run directly on the fieldbus module
(FBM) for reduced latency and improved system responsiveness. Additionally, the FBM204 is fully
electrically compatible with standard HART signals, supporting seamless integration with HART-
enabled field devices for advanced diagnostics and configuration.
Features
Four 20 mA DC analog input channels
• Four 20 mA DC analog output channels
• Each input and output channel is galvanically isolated
• Rugged design suitable for enclosure in Class G3 (harsh) environments
• Execution of an analog I/O application program that provides conversion time and configurable
options for Rate of Change Limits
• High accuracy achieved by sigma-delta data conversions for each channel
• Termination Assemblies (TAs) for locally or remotely connecting field wiring to the Compact FBM204
• TA for use with Output Bypass Station to maintain outputs during maintenance operations
• 3-tier termination assembly for per channel internally and/or externally loop powered transmitters
• Support for DPIDA control blocks
Standard Design
FBM204 has a rugged extruded aluminum exterior for physical protection of the circuits. Enclosures
specially designed for mounting the FBMs provide various levels of environmental protection, up to
harsh environments, per ISA Standard S71.04.
Functional Specifications
Environmental Specifications
Physical Specifications
