Overview
The TU846 (article number 3BSE022460R1) is a redundant Module Termination Unit (MTU) designed
by ABB for the ABB Ability™ System 800xA® platform. As a passive termination component, it is
specifically engineered to support redundant configurations of the CI840/CI840A field
communication interface and redundant I/O modules. It facilitates power supply connection,
redundant ModuleBus distribution, PROFIBUS communication, and station address configuration,
making it a critical component for high-availability industrial automation systems.
Core Functionality
●Redundant Communication Support: Distributes two electrical ModuleBuses to connect with two
CI840/CI840A modules, enabling redundant field communication and I/O connectivity for high-
reliability operations.
●PROFIBUS Integration: Features two PROFIBUS DP-V1 connections (via DSUB9 connectors) and line
redundancy, supporting seamless integration into PROFIBUS-based industrial networks.
●Station Address Configuration: Equipped with two rotary switches for setting station addresses
(range: 0 to 99), allowing flexible system addressing and module identification.
●Mechanical Keying: Includes four mechanical keys (two per module position, 6 positions each) for 36
possible configurations. This mechanical safeguard prevents insertion of incompatible modules
without impacting functional performance.
●Expansion & Service Interfaces: Supports connection to the ModuleBus Optical Port (TB842) via
TB846 for optical communication expansion. Provides two service tool connections (RJ45 connectors)
for system configuration and maintenance.
●Power Supply Distribution: Accepts 24 V DC power input (19.2–30 V) and distributes power to
connected modules, with ModuleBus current distribution rated at 5 V 1.5 A and 24 V 1.5 A.
General Specifications
| Parameter | Details |
| Article Number | 3BSE022460R1 |
| Type | Redundant Module Termination Unit (MTU) for CI840/CI840A & Redundant I/O |
| Connection Protocol | PROFIBUS DP-V1 |
| Redundancy Support | Line redundancy (yes), Module redundancy (yes) |
| Hot Swap Capability | No |
| Power Input | 24 V DC (19.2 – 30 V) |
| Mounting Direction | Vertical or Horizontal |
| Compatible Modules | CI840/CI840A field communication interfaces, redundant I/O modules (paired with TU847 for single I/O modules) |
| Maximum Ambient Temperature | Horizontal: 55 °C (131 °F); Vertical: 40 °C (104 °F) |
| Operating Temperature | 0 – +55 °C (+32 – +131 °F); certifications apply to +5 – +55 °C |
| Storage Temperature | -40 – +70 °C (-40 – +158 °F) |
