ABB TB820V2 ModuleBus Fiber Optic Modem

Product Overview

ABB TB820V2 3BSE013208R1 is a ModuleBus Modem designed for the ABB S800 I/O system. It provides a fiber-optic interface to the ModuleBus while also connecting to the electrical ModuleBus used by local I/O modules. This architecture allows I/O clusters to be distributed over optical communication links and supports installations where a larger number of I/O modules is required.

The communication interface is especially useful in distributed process-control architectures, where reliable communication and electrical isolation are important considerations.

Technical Specifications

The key specifications include:

• Manufacturer: ABB
• Product Family: S800 I/O
• Product Type: ModuleBus Modem / fiber-optic communication interface
• Article Number: 3BSE013208R1
• Communication Protocol: ABB ModuleBus
• Operating Mode: Slave
• Fiber-Optic Ports: 2
• Electrical ModuleBus: Supported
• Typical 24 V DC Consumption: 100 mA
• ModuleBus Electrical Capacity: Up to 12 I/O modules
• Optical ModuleBus: Up to 7 I/O clusters
• Redundancy: No line or module redundancy
• Hot Swap: No
• Protection Class: IP20
• Dimensions: 58 × 170 × 122 mm
• Weight: Approximately 0.3 kg

Communication Architecture

The main role of this device is to bridge the electrical and optical portions of the ModuleBus. The two interfaces are logically part of the same bus, allowing local I/O modules to communicate through an optical distribution structure.

A local cluster can contain up to 12 I/O modules on the electrical ModuleBus. The fiber-optic side can distribute the ModuleBus to as many as seven clusters. This arrangement is useful when the I/O station needs to extend beyond the practical size of a single local group.

A rotary switch provides cluster-number selection from 1 to 7, allowing the optical network to distinguish individual I/O clusters.

Functional Features

Several functions make this communication module suitable for distributed automation installations:

• Dual optical ports for the optical ModuleBus.
• Electrical ModuleBus connection for local S800 I/O modules.
• Power-supply supervision for the associated I/O section.
• ModuleBus supervision for communication monitoring.
• Isolated power supply to connected I/O modules.
• Cluster identification through the rotary selector.
• DIN-rail-oriented S800 I/O architecture for compact cabinet integration.

The design allows process I/O to be placed closer to field equipment while maintaining an optical communication connection with the broader control-system architecture.

Applications in Process Automation

This communication interface can be used in distributed S800 I/O installations where optical ModuleBus communication is required. Typical applications include process plants, power-generation facilities, chemical production, oil and gas systems, water treatment, pulp and paper plants, and other industrial automation environments.

Its optical interface can also help separate distributed I/O sections from electrically noisy areas. By distributing I/O clusters through fiber, system designers can create more flexible cabinet and field-network arrangements.

The S800 I/O platform is designed as a modular process-I/O system that can communicate with parent controllers and PLCs through industrial fieldbus architectures.

Installation and Maintenance

Before installation, verify the cabinet power supply, ModuleBus configuration, fiber connections, cluster numbering, and mechanical mounting arrangement. The unit operates from a 24 V DC supply, with ABB documentation specifying a typical consumption of 100 mA.

Keep optical connectors clean and protected from dust during maintenance. Contamination or incorrect fiber connections can affect communication performance. Technicians should also verify that the cluster selector corresponds to the intended optical ModuleBus configuration.

Environmental conditions should be considered during installation. ABB specifies an operating temperature range of 0 to +55°C, storage temperatures down to -40°C, relative humidity of 5–95% non-condensing, and IP20 protection. ABB documentation also lists certifications and approvals for several hazardous-location and marine applications.

Replacement and System Compatibility

When replacing an existing unit, confirm the complete article number, hardware version, optical connections, and surrounding S800 I/O configuration. The component is specifically identified by ABB as the TB820V2 ModuleBus Modem, article number 3BSE013208R1.

For industrial maintenance projects, this module is particularly relevant when an existing S800 I/O installation requires replacement of a communication interface without redesigning the complete I/O architecture.