Configured for redundant configuration of Optical ModuleBus Modems in S800 I/O distributed control network platforms, the ABB TU840 (3BSE020846R1 Module Termination Unit) provides direct physical electrical execution for power supply routing, double ModuleBus connectivity, and cluster address management.

Component Configuration and Matrix

• Base Model: TU840
• Ordering Part Number: 3BSE020846R1
• Function: Passive redundant termination and signal distribution
• Series: S800 I/O

Hardware Specifications

Deterministic Industrial Control Integration

The TU840 facilitates deterministic backplane communication by providing the physical infrastructure for redundant TB840/TB840A modem setups. The unit supports I/O density scaling through its dual ModuleBus interface, ensuring consistent data throughput across distributed nodes. The hardware architecture maintains strict backplane bus communication velocity and allows for firmware flash compatibility as part of the broader I/O station assembly, maintaining signal integrity and synchronization required for high-speed industrial process control.

Ordering Info

• 1 unit: TU840 Module Termination Unit
• 1 set: Mechanical keying set for module type configuration
• 1 unit: Technical instruction manual

Field Installation Guidelines

• Mechanical Mounting:
  • Install the unit on a standard 35 mm DIN rail in either a vertical or horizontal orientation.
  • Engage the integrated latching device to ensure mechanical locking and electrical ground contact with the rail.
• Configuration Procedures:
  • Adjust the front-mounted rotary switch to the required cluster address (range 1 to 7).
  • Configure the four mechanical keys (two per position) using a screwdriver to align with the specific module type to prevent incorrect insertion.
  • Ensure all ModuleBus and power supply cables are seated firmly in the terminal connectors.

Frequently Asked Questions

• Q: Is the TU840 an active or passive hardware component?

  A: The TU840 is a passive Module Termination Unit (MTU) designed to provide physical connectivity and routing for redundant modems and power supplies.

• Q: Does the TU840 support redundant I/O configurations?

  A: Yes, it is specifically engineered to support redundant configurations for the TB840/TB840A Optical ModuleBus modems.

• Q: What is the purpose of the rotary switch on the front panel?

  A: The rotary switch is utilized to set the cluster address (1 through 7) for the associated I/O station within the ModuleBus architecture.

• Q: How many mechanical key configurations are possible?

  A: There are 36 different possible mechanical keying combinations, selectable via the four keys to ensure the correct module type is inserted.

• Q: Can the unit be mounted in both horizontal and vertical orientations?

  A: Yes, the design permits both vertical and horizontal mounting on a standard 35 mm DIN rail.

• Q: What is the dielectric test voltage rating?

  A: The unit is rated for a dielectric test voltage of 500 VAC.

• Q: Does the unit include internal current limiting for the ModuleBus?

  A: It handles up to 1.5 A for both 5 V and 24 V rails; however, it does not replace the need for external system-level overcurrent protection.

• Q: What is the maximum storage temperature for the TU840?

  A: The unit can be stored in environments ranging from -40 to +70 deg C (-40 to +158 deg F).