Description

ABB TU849 3BSE042560R1 Module Termination Unit

The ABB TU849 3BSE042560R1, also cataloged as the TU849 Module Termination Unit, provides physical termination and power distribution for redundant TB840/TB840A Optical ModuleBus Modem configurations within ABB ModuleBus networks.

Hardware Specifications

Parameter	Specification
Model	TU849 3BSE042560R1
Brand	ABB
Origin	Sweden
Product Type	Module Termination Unit (MTU)
Communication Protocol	ModuleBus
Configuration Type	Redundant TB840/TB840A, Single I/O, Dual Power
Power Input	24 VDC (19.2 to 30 V)
Weight	0.45 kg
Dimensions	124 mm W x 186.5 mm H x 47 mm D
Mounting	Vertical or Horizontal DIN rail mounting
Operating Temp	0 to +55 deg C (approved range +5 to +55 deg C)
Storage Temperature	-40 to +70 deg C
Power Consumption	2.5 W
ModuleBus Current Distribution	Maximum 5 V 1.5 A and 24 V 1.5 A
Line Redundancy	Yes
Hot Swap Support	No
Mechanical Key Configurations	36 selectable combinations
Rated Insulation Voltage	50 V
Dielectric Test Voltage	500 VAC
Protection Class	IP20 according to IEC 60529
Relative Humidity	5 to 95 %, non-condensing
Wire Size Range	Solid and stranded 0.2 to 2.5 mm2, 24 to 12 AWG
Recommended Terminal Torque	0.5 Nm

ABB ModuleBus Redundant Power and I/O Interface Design

The TU849 uses passive electrical routing to connect two TB840/TB840A Optical ModuleBus Modems with individual power supply inputs. The unit provides one electrical ModuleBus connection and supports redundant modem installation for non-redundant I/O configurations.

Furthermore, the MTU integrates a rotary switch for cluster address selection from 1 to 7. Four mechanical keys define module compatibility through 36 selectable hardware configurations. The key positions can be adjusted with a screwdriver to match the installed modem arrangement.

For ABB industrial control platforms, the TU849 supports ModuleBus communication structures where backplane bus communication velocity and I/O density scaling depend on the connected controller and I/O architecture. The passive termination design maintains direct signal routing without internal processing functions.

Frequently Asked Questions

Q: Does the ABB TU849 support hot swap replacement of TB840/TB840A modules?
A: No. The TU849 does not provide hot swap capability. Power isolation and system shutdown procedures should be followed before replacing connected modem modules.

Q: What type of power connection does the TU849 provide for redundant modem installation?
A: The TU849 provides two separate power supply connections, with one connection assigned to each TB840/TB840A modem position.

Q: How are module compatibility settings configured on the TU849?
A: The MTU uses four mechanical keys with six positions each. These settings provide 36 possible hardware configurations and can be adjusted using a screwdriver.

Field Installation Guidelines

Install the TU849 on a standard DIN rail using the integrated mechanical latch. Verify that the latch is correctly locked after mounting to prevent mechanical movement during operation.

Connect the 24 VDC power supply lines according to the assigned modem positions. Maintain correct polarity and separate power routing for each redundant modem connection.

Use approved industrial wiring practices when connecting ModuleBus and power conductors. Keep signal cables separated from high-voltage switching circuits to reduce electrical interference.

Before operation, verify the rotary switch cluster address setting and confirm that the mechanical key configuration matches the installed TB840/TB840A modem type.

Specifications

• Brand: ABB

Advantages

• High reliability in industrial environments
• Supports continuous operation
• Compatible with major PLC/DCS systems