Description

The Foxboro FBM203 is a high-accuracy,isolated thermocouple input module designed for the Foxboro I/A Series®Distributed Control System(DCS).Developed by Schneider Electric(which acquired Invensys and the Foxboro brand),the FBM203 provides reliable temperature measurement in demanding process industries such as oil&gas,power generation,chemicals,and pharmaceuticals.

As part of the Fieldbus Module(FBM)family,the FBM203 interfaces directly with Type J,K,T,E,R,S,B,and N thermocouples,automatically compensating for cold-junction temperature and supporting sensor open-circuit detection.It delivers 16-bit resolution and high noise immunity—critical for precise combustion control,reactor monitoring,or turbine exhaust temperature tracking.

Application Scenarios

At a combined-cycle power plant in Texas,operators struggled with inconsistent boiler tube metal temperature readings due to ground loops and EMI from nearby VFDs.After replacing legacy analog cards with Foxboro FBM203 modules,they achieved:

±0.25%accuracy across 0–1200°C

Reliable open-circuit alarms within 1 second of sensor failure

Full integration with I/A Series alarm management and historian trending

During a catalyst regeneration event in a refinery reactor,the FBM203’s fast diagnostics flagged a drifting Type K thermocouple before it caused an unsafe temperature excursion—demonstrating how precision sensing becomes a safety asset.

Key Technical Specifications

Parameter Specification

Model FBM203

Manufacturer Schneider Electric(Foxboro I/A Series)

Function 8-channel isolated thermocouple input module

Compatible Sensors J,K,T,E,R,S,B,N(selectable per channel via configuration)

Input Range Varies by type(e.g.,K:-200 to+1372°C;R/S:0 to 1768°C)

Resolution 16-bit A/D conversion

Accuracy±0.25%of span(typical),including cold-junction compensation

Cold-Junction Compensation(CJC)Built-in precision sensor at terminal block

Isolation Channel-to-channel and field-to-system isolation(500 VAC RMS)

Update Rate~100 ms per channel(configurable via FBM parameters)

Open-Circuit Detection Yes–reports fault within 1–2 scan cycles

Terminal Block Removable screw-type(accepts 14–22 AWG wire)

Mounting Plugs into Foxboro I/O Pack chassis(e.g.,FBM housing in I/A Series cabinets)

Redundancy Supports redundant FBM configurations(with FBM203R variant or dual I/O packs)

Communications Connects to Field Control Processor(FCP)via I/O Link(proprietary high-speed bus)

LED Indicators Module OK,Fault,Network Activity

Operating Temperature 0°C to+60°C

Certifications CE,UL,CSA,ATEX/IECEx(for hazardous area variants)

🔍Note:The standard FBM203 is non-redundant.For critical applications(e.g.,turbine protection),use the FBM203R(redundant version)or pair with redundant I/O packs and FCPs.

System Integration in I/A Series Architecture

text

编辑

Thermocouples(Field)

↓

FBM203 Terminal Block(with CJC sensor)

↓

FBM203 Module→Converts mV to engineering units

↓

I/O Pack Backplane→Sends data to Field Control Processor(FCP)

↓

FCP→Executes control logic,alarms,and communications

↓

Operator Stations(via I/A Series Workbench or SCADA)

Configuration is performed in I/A Series Workbench or Control Builder.

Each channel is assigned a block name,engineering units,alarm limits,and fail-safe behavior.

Data is available for trending,batch reporting,and asset management via AIMS or AVEVA PI System.

Key Features&Innovations

✅Per-Channel Sensor Type Selection

No hardware changes needed—configure each of the 8 channels independently for different thermocouple types via software.

✅True Cold-Junction Compensation at Terminal

Unlike modules that estimate CJC internally,the FBM203 measures ambient temperature directly at the terminal block,minimizing error from cabinet heat.

✅Robust Diagnostics

Open-circuit(broken wire)

Short-circuit detection

Out-of-range signals

Module self-test on power-up

✅High Common-Mode Rejection

120 dB CMRR ensures stable readings even with ground potential differences in large plants.

Common Issues&Best Practices

⚠️Wiring Tips:

Use twisted-pair,shielded thermocouple extension wire.

Ground shield at the FBM203 end only(avoid ground loops).

Do not run thermocouple wires parallel to power cables(>30 cm separation recommended).

🔧Configuration Tips:

Always enable open-circuit detection in critical loops.

Set reasonable rate-of-change alarms to catch sensor drift.

Verify CJC sensor health during calibration—replace terminal block if damaged.

🔄Redundancy Note:

For SIL-rated or critical safety functions,ensure you are using the FBM203R(redundant I/O)with dual FCPs and voting logic.

Related Modules in Foxboro I/A Series

Module Function

FBM201 8-channel RTD input

FBM202 8-channel 4–20 mA input(isolated)

FBM204 8-channel 4–20 mA output

FBM207 Pulse input(for flow meters)

FBM237 High-density thermocouple(16-channel)

FBM242 HART-enabled analog input

FBM203R Redundant version of FBM203

Availability&Support

We supply genuine,tested Foxboro FBM203 modules—new surplus or factory-refurbished—with:

Full functional test(all 8 channels,CJC validation,open-circuit test)

Compatibility verification with your I/A Series version(e.g.,v8.x,v9.x)

Original terminal blocks and mounting hardware

12-month warranty

Our Foxboro-certified engineers offer:

Configuration file review

Replacement guidance(including FBM203 vs.FBM237 trade-offs)

Calibration procedure support

Migration planning to EcoStruxure™Foxboro DCS or AVEVA System Platform

Final Note

The Foxboro FBM203 represents decades of refinement in industrial temperature measurement—combining precision,reliability,and seamless DCS integration.In processes where a few degrees can mean the difference between efficiency and failure,this module delivers trusted insight,one millivolt at a time.

Contact us for datasheets,wiring diagrams,GSD files(if used with PROFIBUS gateway),or emergency spares for your I/A Series system.

选择深圳长欣，选择放心，售后无忧 大量现货，当天顺丰发货！！！