FOXBORO FBM42 Fieldbus IO Interface Module Legacy IA Series

📣The FOXBORO FBM42 is a DNBI (Dual Node Bus Interface) fieldbus gateway module for the Foxboro I/A Series DCS (Schneider Electric / Invensys heritage). It bridges the I/A Series control processor with a DeviceNet field network, enabling real-time data exchange between the DCS and smart field devices such as drives, valve actuators, motor starters, sensors, and remote I/O.

Built for process automation retrofits and greenfield integration, it converts DeviceNet object/model traffic into the I/A Series backplane data space, so operators can monitor and command device-level assets directly from the control room.

🧾Key Specifications

Specification	Detail
Brand	FOXBORO
Model	FBM42
Module Type	DNBI – DeviceNet Fieldbus Interface / Dual Node Bus Interface
System Compatibility	Foxboro I/A Series DCS (CP40/CP60 class controllers, FBM I/O)
Fieldbus Protocol	DeviceNet (ODVA CIP over CAN)
Baud Rates	125 / 250 / 500 kbps, software-selectable, auto-baud detect
Node Address	0–63 (MAC ID), rotary/software setting
Max Field Devices	Up to 63 nodes per DeviceNet segment
Comm Modes	Polled, strobed, cyclic, status-change, explicit messaging
Backplane Power	24 V DC (typical 24 VDC ±10%)
Power Consumption	< 8 W (typical)
Isolation	Electrical isolation between DeviceNet trunk and DCS backplane
Indicators	LED status: power, network OK, node active, faults
Diagnostics	Network load, error counters, node online/offline, fault buffering
Mounting	I/A Series rack / DIN-rail carrier
Operating Temp.	0 °C to +60 °C (industrial grade)
Storage Temp.	–40 °C to +85 °C
Environment	G3 harsh-site capable, EMC hardened
Hot-Swap	Supported in redundant I/A configurations
Certifications	CE, UL/cULus, ODVA conformance (typical)

Product Overview

The FBM42 sits between the I/A Series controller and the device-level network. On the DeviceNet side it acts as a scanner/slave bridge; on the DCS side it maps I/O data into the control database without custom glue logic.

Its dual-processor architecture separates:

DeviceNet stack handling (connection management, CIP objects, I/O polling)
DCS data exchange (backplane DMA, tag mapping, time synchronization)

This keeps scan cycles deterministic even with many nodes, and lets maintenance staff add/remove devices online without stopping the controller.

Core Features

1. DeviceNet-to-DCS Protocol Bridge

Connects I/A Series DCS to DeviceNet-enabled field devices:

Variable frequency drives
Smart valves & positioners
Motor control centers / soft starters
Remote I/O blocks, encoders, safety relays

2. Flexible Communication Modes

Supports polling, cyclic, status-change, and explicit messaging per ODVA DeviceNet spec, so both high-speed control data and configuration/diagnostic data share one cable.

3. Dual-Node Bus Architecture

Provides resilient dual-path bridging inside the I/A rack; in redundant pairs it supports automatic switchover to avoid communication loss.

4. Online Device Management

Auto-detect node type and firmware
Central parameterization & firmware push
Online add/remove of slaves
Live network health monitoring

5. Industrial-Grade Reliability

Galvanic isolation, surge/ESD protection, G3 corrosion tolerance, and LED-driven diagnostics make it suitable for refineries, power plants, and heavy manufacturing.