Product Overview

The Foxboro RH916DB is an I/A Series termination cable used to connect field termination hardware with the associated I/A Series I/O equipment. It forms part of the cabinet-level interconnection between the field wiring termination section and the electronic I/O section of a Foxboro process-control system.

In an I/A Series installation, field instruments are normally connected through an organized termination arrangement before their circuits reach the electronic I/O hardware. The RH916DB carries the corresponding electrical connections between these system sections, helping maintain a structured signal path inside the control cabinet.

The RH916DB is a passive cable assembly rather than an active I/O device. It does not independently process field signals or execute control logic. Its function is to preserve the electrical connection between the termination arrangement and the associated I/O interface.

For maintenance and replacement work, the cable should be considered together with the termination assembly, associated I/O hardware, cabinet wiring, and applicable system drawings. Correct identification of both ends is particularly important because the cable forms part of the fixed point-to-point signal architecture.

Technical Specifications

Product Features

• Termination cable for Foxboro I/A Series control-system installations
• Connects termination hardware with associated I/A Series I/O equipment
• Functions as a passive electrical signal interconnection
• Supports organized field I/O wiring inside control cabinets
• Maintains the physical separation between field termination and electronic I/O hardware
• Suitable for established Foxboro I/A Series installations
• Useful for replacement of existing termination cables during maintenance
• Supports structured routing of field signal connections
• Suitable for cabinet refurbishment and retrofit service work
• Helps preserve the existing I/A Series I/O wiring architecture

Working Principle

The RH916DB provides the electrical path between an I/A Series termination arrangement and the corresponding I/O hardware. It carries the circuit connections without independently interpreting, conditioning, or processing the process signals.

For an input circuit, the general signal path can be represented as:

Field Device → Field Wiring → Termination Hardware → RH916DB → I/A Series I/O Hardware → Control System

A transmitter, switch, or other field instrument sends its signal through the field wiring to the termination hardware. The RH916DB then carries the associated connection toward the I/O interface, where the applicable I/A Series electronics process the signal.

For an output circuit, the direction is reversed:

Control System → I/A Series I/O Hardware → RH916DB → Termination Hardware → Field Device

In this arrangement, the cable carries the output connection toward the field device through the termination hardware.

Because the RH916DB is part of a fixed interconnection, correct cable identification is essential during maintenance. Both ends should be matched to the appropriate termination and I/O interfaces using the cabinet drawings or termination documentation. A physically connected cable can still create an incorrect signal path if it is installed at the wrong connection point.

Role in a Foxboro I/A Series I/O Control Architecture

The RH916DB occupies the interconnection layer between the field termination hardware and the electronic I/O section. It maintains the physical signal path while leaving signal processing and control functions to the associated I/A Series electronics.

Industrial Applications

Installation and Maintenance

1. Confirm the part number — Verify that the RH916DB matches the existing I/A Series termination and I/O arrangement before installation.
2. Review system documentation — Check cabinet drawings, termination schedules, and I/O documentation to identify the intended connection points.
3. Isolate the relevant equipment — Follow the plant’s approved shutdown, isolation, and electrical safety procedures before disconnecting the existing cable.
4. Identify both cable ends — Confirm the termination-side and I/O-side connection points before removing the installed cable.
5. Inspect the cable assembly — Check the cable and accessible connection areas for physical damage, contamination, corrosion, or other visible abnormalities.
6. Remove the existing cable carefully — Disconnect both ends according to the applicable maintenance procedure without applying unnecessary force to the connectors or adjacent wiring.
7. Verify the cable routing — Confirm that the replacement follows the established cabinet routing and does not interfere with nearby equipment or wiring.
8. Install the replacement cable — Connect the RH916DB to the correct termination and I/O interfaces and ensure that both connections are fully seated.
9. Check connection identification — Compare both ends with the cabinet documentation to prevent incorrect point-to-point connections.
10. Perform continuity verification — Where applicable, verify the completed cable path before restoring the I/O section to normal operation.
11. Perform a controlled signal check — Confirm representative input or output points and investigate any unexpected signal behavior after installation.
12. Document the maintenance work — Record the installed cable model, associated termination hardware, I/O equipment, and test results for future service activities.

Related Components

Recommended Related Models

Key Advantages

• Provides a dedicated electrical connection between I/A Series termination and I/O hardware.
• Maintains the established field-wiring architecture of Foxboro control cabinets.
• Functions as a passive signal path without independent signal processing.
• Supports organized routing of field I/O connections.
• Suitable for maintenance and replacement of existing I/A Series installations.
• Helps preserve established point-to-point wiring during cabinet service work.

Technical FAQs

What is the purpose of the Foxboro RH916DB?

The RH916DB is an I/A Series termination cable used to connect termination hardware with associated I/A Series I/O equipment. It carries the corresponding electrical connections without independently processing the signals.

Is the RH916DB an active I/O component?

No. The RH916DB is a passive cable assembly. Signal processing and control functions are performed by the associated I/A Series I/O and control-system hardware.

What should be checked before replacing the RH916DB?

The termination arrangement, associated I/O hardware, cable connection points, cabinet documentation, and routing should be verified before removing the existing cable. Both ends should be positively identified before reconnection.

What should be checked after installing a replacement termination cable?

The cable connections should be checked against the system documentation, followed where applicable by continuity verification and a controlled signal test. Any unexpected signal loss or incorrect point indication should be investigated before returning the system to normal operation.