Foxboro FBM242 Discrete Output Module

Description

Product Summary

The Foxboro FBM242 is a 16-channel discrete output module designed to interface a Foxboro control processor with field devices requiring switched electrical outputs. It uses an external field power source and supports multiple output arrangements through compatible termination assemblies, including low-voltage DC switching, relay outputs, and solid-state switching options.

Each output channel is galvanically isolated from the other channels and ground. The module supports configurable discrete I/O or ladder logic applications, including fail-safe output behavior and sustained or momentary output operation. Front-panel LEDs indicate module status and individual output states, helping maintenance personnel identify operating conditions during commissioning and troubleshooting.

Product identification

• Brand: Foxboro by Schneider Electric
• Model: FBM242
• Module part number: RH916TA
• Legacy module part number: P0916TA
• Product type: Externally sourced discrete output module
• Channel count: 16 discrete outputs
• System family: Foxboro Evo / I/A Series 200 Series architecture

 

Technical Specifications

Parameter	Specification
Model	FBM242
Current module part number	RH916TA
Previous part number	P0916TA
I/O type	Discrete output
Number of channels	16 isolated output channels
External output voltage	15–60 V DC for the module’s low-voltage output interface
Maximum channel load current	2.25 A per channel under specified conditions
Maximum inrush current	8 A for 20 ms per channel at 30°C; 6.4 A for 20 ms at 70°C
Maximum on-state voltage drop	0.2 V at 2.25 A
Maximum off-state leakage	0.1 mA
Channel isolation	Galvanic isolation between channels and ground
Isolation withstand	600 V AC for one minute under the manufacturer’s specified test conditions
Module supply	24 V DC, +5% / −10%
Maximum module power consumption	3 W at 24 V DC
Maximum heat dissipation	6.5 W at 24 V DC under the specified loading condition
Fieldbus	Redundant 2 Mbps module Fieldbus
Operating temperature	−20°C to +70°C
Storage temperature	−40°C to +70°C
Relative humidity	5–95%, noncondensing
Harsh-environment classification	Suitable for Class G3 environments under ISA S71.04
Module dimensions	102 mm high; 114 mm including mounting lugs × 45 mm wide × 104 mm deep
Approximate module weight	284 g
Mounting	Modular baseplate; DIN rail or compatible 19-inch rack installation
Calibration	No module calibration required

Important: These electrical ratings describe the module’s specified interface. The actual field switching voltage, current limit, relay rating, fusing, and power-distribution arrangement depend on the selected termination assembly. Confirm the exact assembly and its ratings before connecting field loads.

 

Key Features and Engineering Advantages

Sixteen Discrete Output Channels

The FBM242 provides 16 output points in a single module position. This supports the control of multiple discrete field devices without allocating a separate module for each signal.

Flexible Output Arrangements

Compatible termination assemblies provide different switching arrangements. Depending on the assembly, applications can use low-voltage DC switches, electromechanical relays, or solid-state switches. Some assemblies include fuses or field-power distribution.

Galvanic Channel Isolation

Each output channel is galvanically isolated from other channels and ground. This isolation helps separate electrical circuits and supports reliable integration when correctly applied within the system’s specified limits.

Configurable Output Behavior

The module supports discrete I/O and ladder logic applications. Configurable functions include fail-safe configuration, fail-safe fallback, and sustained or momentary output operation, subject to the applicable control-system configuration.

Diagnostic Indicators

Front-panel LEDs show module operating status and individual output states. These indicators provide a practical first check when investigating a commanded output that does not produce the expected field response.

Redundant Fieldbus Communication

The FBM242 communicates over the redundant 2 Mbps module Fieldbus and can accept communications through either path A or path B. If one path fails or is switched at the system level, communication can continue through the active path, subject to the system configuration.

Serviceable Installation

The module is designed for removal and replacement without disconnecting field-device termination wiring, field power, or communication cabling. Follow the applicable Foxboro maintenance procedures and site safety requirements when replacing a module.

System Compatibility and Integration Requirements

The FBM242 is intended for compatible Foxboro Evo or I/A Series 200 Series control-system installations. Successful integration depends on more than matching the module name.

Before ordering or installing a replacement, verify:

• The existing module part number and hardware revision.
• The installed baseplate and its mechanical and electrical compatibility.
• The compatible control processor or Fieldbus Communications Module (FCM).
• The termination assembly part number and its output configuration.
• The field supply voltage, load current, inrush current, and switching technology.
• The configured output behavior, including fail-safe settings.
• The termination cable type, connector, and required cable length.

The module connects to the control system through the redundant 2 Mbps module Fieldbus. Field I/O wiring connects through a separate termination assembly and removable termination cable.

Part-number distinction: RH916TA is the standard module part number identified in the manufacturer’s specification as superseding P0916TA. Termination assemblies have their own part numbers and are not interchangeable solely because they are listed for FBM242.

 

Mounting, Wiring, and Installation Notes

Mounting

The module installs on a compatible modular baseplate. The baseplate can be mounted horizontally or vertically on a DIN rail, or horizontally in a 19-inch rack using the appropriate mounting kit.

The field termination assembly is mounted separately on a DIN rail and connects to the subsystem through a termination cable.

Wiring and External Power

The FBM242 is an externally sourced output module. The field circuits therefore require a suitable external power arrangement where specified by the selected termination assembly.

Check the following before energizing the installation:

1. Confirm the termination assembly is approved for the intended voltage and load type.
2. Verify per-channel current and aggregate current limits.
3. Check the fusing and power-distribution arrangement.
4. Confirm the termination cable and connector match the installed hardware.
5. Provide appropriate suppression for inductive loads where required.

For DC inductive loads, the manufacturer’s guidance specifies a protective diode where applicable. For AC inductive loads, a suitably rated metal-oxide varistor (MOV) may be required. Select the protection device according to the actual load and supply conditions.

Replacement and Commissioning

Before removing a module, follow site lockout/tagout requirements and the system’s approved replacement procedure. After installation, verify module recognition, fieldbus communication, output indications, field supply, and commanded operation at each relevant output point.

 

Product Overview

The Foxboro FBM242 performs the discrete output stage between control-system logic and field equipment. It receives output commands through the Foxboro module Fieldbus and provides 16 isolated output channels for the configured field interface.

Its externally sourced design allows the field circuit arrangement to be selected through compatible termination assemblies. This is useful in installations where output loads require different switching technologies or protection arrangements. For example, low-voltage DC loads may use a suitable fused switching assembly, while other applications may require relay or solid-state output hardware.

The termination assembly is therefore a critical part of the installation, not an optional detail to be ignored during replacement. An FBM242 module and a termination assembly should be evaluated together against the original wiring design and load characteristics.

For maintenance teams, the front-panel status indicators, redundant Fieldbus support, and replaceable module design help simplify fault isolation and module service. However, an output indication alone does not confirm that the external supply, field wiring, termination hardware, and connected device are all functioning correctly.

When sourcing an FBM242 for an installed control system, prioritize exact part-number verification, termination compatibility, hardware condition, and confirmation of the required system configuration.

 

Applications

The FBM242 can be used wherever a compatible Foxboro control system must operate discrete field loads. Typical application categories include:

• Process control: Switching discrete devices as part of configured control sequences.
• Industrial machinery: Issuing on/off commands to compatible actuators and interface circuits.
• Utilities and energy: Controlling discrete equipment interfaces in process and utility installations.
• Chemical and petrochemical facilities: Integrating field switching signals with distributed control logic.
• Manufacturing systems: Operating discrete devices through a centralized control platform.
• Legacy system maintenance: Replacing an existing FBM242 in a compatible installed base.

The suitability of any application depends on the selected termination assembly, electrical load, system configuration, and applicable safety requirements.

 

Frequently Asked Questions

What is the Foxboro FBM242?

The FBM242 is a 16-channel externally sourced discrete output module for compatible Foxboro process automation systems.

What is the module part number for FBM242?

The manufacturer’s standard specification identifies RH916TA as the module part number, superseding the legacy P0916TA designation.

Does the FBM242 require an external power supply?

Yes. The field output circuits use external power as required by the selected termination assembly. The module itself also requires its specified 24 V DC supply.

What output voltages does the FBM242 support?

The module specification describes a low-voltage output interface of 15–60 V DC. Compatible termination assemblies provide additional switching arrangements, including relay and solid-state outputs for specified AC or DC loads. The precise limits depend on the selected assembly.

Is each FBM242 output channel isolated?

Yes. The module specification states that each channel is galvanically isolated from the other channels and ground.

Can the FBM242 communicate over a redundant Fieldbus?

Yes. It communicates over the redundant 2 Mbps module Fieldbus and can accept communication through either path A or path B.

Does the FBM242 need calibration?

The manufacturer’s specification states that the module and its termination assemblies require no calibration.

What should be checked when replacing an FBM242?

Verify the module part number, baseplate compatibility, termination assembly, field voltage, load current, wiring, termination cable, control-system configuration, and output behavior before returning the system to service.

Are FBM242 and Compact FBM242 the same product?

They are related Foxboro product variants, but the standard and Compact versions have separate product specifications and may use different hardware arrangements. Confirm the exact installed variant and its documentation before purchasing a replacement.

How can the correct FBM242 termination assembly be selected?

Select it according to the field voltage, switching technology, load current, fusing, isolation, and power-distribution requirements. Match the existing assembly part number wherever possible, then verify its current manufacturer specification.

 

Manufacturer Reference

For definitive electrical limits, termination assembly selection, installation requirements, and certification details, consult the Schneider Electric / Foxboro product specification for FBM242 and the documentation for the specific termination assembly used in the installation.