Product Overview

The Foxboro RH916NC I/A Series Module Fieldbus Cable is a 3-meter cable used to connect compatible Fieldbus Modules (FBMs) to their associated termination assemblies in Foxboro I/A Series distributed control systems. It belongs to the module fieldbus cabling family used to establish the physical connection between control-system I/O hardware and field termination equipment.

In a modular DCS installation, FBMs process field signals and exchange information with the control system, while termination assemblies provide the connection between module interfaces and field wiring. The RH916NC supports this arrangement by providing the required cable connection for compatible hardware configurations.

The RH916NC is the LSZH cable version associated with the earlier P0916NC designation. The corresponding LSZH part number P0928BQ is also listed in Foxboro module fieldbus cable documentation. These designations should be distinguished when checking replacement requirements because cable construction, environmental characteristics, and system compatibility may vary between versions.

The cable is relevant to maintenance work involving existing I/A Series installations, particularly when a damaged connection must be replaced or an established FBM-to-termination assembly connection must be restored. Before installation, engineers should verify the cable type, connector arrangement, module configuration, and termination assembly requirements against the actual system documentation.

Technical Specifications

Product Features

• Module fieldbus connection: Supports the physical connection between compatible Fieldbus Modules and their associated termination assemblies.
• 3-meter cable length: Provides a defined cable length for installations requiring the corresponding connection distance.
• LSZH cable construction: Uses a low-smoke, zero-halogen jacket material classification.
• I/A Series integration: Supports compatible Foxboro modular control-system cabling arrangements.
• Replacement compatibility: Provides an alternative cable designation for installations where the RH916NC version is specified.
• Fieldbus infrastructure support: Helps maintain the connection between module hardware and field termination equipment.
• Configuration-specific selection: Requires verification of the module type, termination assembly, and connector arrangement before installation.

Working Principle

The RH916NC provides the physical cable connection required for a compatible Foxboro I/A Series fieldbus module and termination assembly arrangement. It carries the relevant electrical signals between the connected interfaces; the cable itself does not perform signal conversion, execute control logic, or process field measurements.

A typical field I/O connection follows this general path:

Field Device → Field Wiring → Termination Assembly → RH916NC Cable → Fieldbus Module → Control System

For input applications, field signals pass through the field wiring and termination assembly to the appropriate FBM channels. The FBM processes the incoming signals according to its specific function and makes the resulting data available to the control system. For output applications, the signal path operates in the opposite direction, allowing the control system to send commands to compatible field equipment.

The precise electrical arrangement depends on the FBM model, termination assembly, and installed system configuration. The RH916NC must therefore be selected for the intended module-to-termination connection rather than treated as a universal cable for every I/A Series interface.

Cable construction also matters. LSZH refers to low-smoke, zero-halogen material characteristics. Compared with conventional halogen-containing cable jackets, LSZH materials are intended to limit smoke and halogen emissions under specified fire conditions. This classification does not, by itself, establish the cable’s electrical rating, connector compatibility, or suitability for every installation environment.

When communication or field I/O faults occur, technicians should inspect the cable, connector seating, termination assembly, and module status. A damaged or incorrectly connected cable can interrupt the signal path, but similar symptoms may also result from faulty field wiring, a defective termination assembly, or a problem within the FBM.

Role in the Foxboro I/A Series Control Architecture

The RH916NC supports the field I/O connection between compatible FBMs and termination assemblies in the Foxboro I/A Series architecture. It provides the physical link needed to transfer field signals between the termination hardware and the associated module.

Field Devices → Field Wiring → Termination Assembly → RH916NC → FBM → Control Processor

The cable does not replace the termination assembly or FBM. Correct operation depends on the compatibility and condition of all components in the field I/O path.

Industrial Applications

Application suitability depends on the FBM model, termination assembly, cable construction, and installed system architecture. Confirming these details before replacement helps prevent incorrect connections and unnecessary troubleshooting.

Installation and Maintenance

1. Verify the part number: Confirm that RH916NC is the required cable for the intended Foxboro I/A Series fieldbus connection.
2. Check module compatibility: Identify the installed FBM and confirm that its interface supports the specified cable arrangement.
3. Confirm the termination assembly: Verify the associated termination assembly model and its compatibility with the module and cable.
4. Review the wiring drawings: Identify the correct module and termination assembly connection points before disconnecting existing cabling.
5. Follow isolation procedures: Apply the site’s approved maintenance and electrical isolation procedures before working on the control hardware.
6. Inspect the cable jacket: Check for cuts, crushing, abrasion, deformation, or other visible damage that could compromise the cable.
7. Examine the connectors: Look for bent contacts, contamination, damaged housings, or other signs of poor connection integrity.
8. Connect the cable correctly: Align the connectors with their intended interfaces and secure them according to the applicable installation instructions.
9. Route the cable carefully: Avoid sharp bends, excessive tension, crushing, and contact with sharp cabinet edges.
10. Maintain appropriate cable separation: Follow the system’s wiring practices for routing fieldbus cables near power wiring or other potential interference sources.
11. Verify field I/O operation: After installation, check the module status, system diagnostics, and relevant field signals to confirm that the connection operates as expected.
12. Document the replacement: Record the installed part number, connected hardware, and commissioning results in the maintenance records.

If a field signal remains unavailable after cable replacement, inspect the termination assembly, field wiring, FBM status, and control-system configuration. Confirm the fault location before replacing additional components.

Compatible System Components

The RH916NC is intended for compatible Foxboro I/A Series module fieldbus connections. The associated hardware must match the cable’s designated function and the system’s field I/O architecture.

Recommended Related Models

Key Advantages

• Supports the field I/O connection between compatible FBMs and termination assemblies.
• Provides a 3-meter cable option for the specified installation arrangement.
• Uses LSZH cable construction for applications requiring low-smoke, zero-halogen materials.
• Supports maintenance and replacement of compatible I/A Series fieldbus cabling.
• Helps maintain the intended field-signal path when installed with compatible system hardware.

Technical FAQs

What is the difference between RH916NC and P0916NC?

RH916NC is the LSZH version associated with the earlier P0916NC designation. The corresponding LSZH part number P0928BQ is also listed for the 3-meter module fieldbus cable. Confirm the required cable construction and connector configuration before selecting a replacement.

Does the RH916NC connect a fieldbus module directly to a field device?

Its intended role is within the module-to-termination assembly connection. Field devices normally connect through field wiring and the appropriate termination hardware. The exact arrangement depends on the FBM and termination assembly used in the installation.

Why should the termination assembly model be checked before replacing this cable?

Termination assemblies are designed for specific module interfaces and field wiring arrangements. A cable with the correct length may still be unsuitable if the associated hardware or connector arrangement differs. Verify the complete connection configuration before installation.

What is the practical significance of the LSZH cable construction?

LSZH stands for low smoke, zero halogen. This material classification is relevant where smoke and halogen emissions under fire conditions are important installation considerations. It does not independently establish electrical compatibility, fire certification for a specific installation, or suitability for every operating environment.