The ABB NDBU-95, also cataloged as the NDBU-95 DDCS Branching Unit, operates as a dedicated hardware component for optical signal fan-out and multi-channel drive network distribution within ABB Drives architectures.

System Classification & Part Cross-Reference

• Primary Product Model: NDBU-95

• Spare Part Designation: 63985252D

• Functional Topology: 1-to-9 Channel Plastic Optical Fiber (POF) Splitter

• Coating Variant: NDBU 95-COAT

Hardware Specifications

Optical Bus Topology & Deterministic Drive Execution

The NDBU-95 branching unit splits incoming Distributed Drives Communication System (DDCS) optical signals across up to nine downstream drive channels without altering data telegram structures. Supporting high backplane bus communication velocity across fiber topologies, the module maintains firmware flash compatibility with master controllers such as the AC800M or legacy drive controller platforms. Optical routing eliminates electromagnetic susceptibility across long cable runs, maintaining deterministic signal propagation without inducing transmission delays or noise corruption.

Package Delivery Contents

• 1 x ABB NDBU-95 DDCS Branching Unit (63985252D)

Site Installation & Fiber Routing Guidelines

• Mount the unit securely to the interior enclosure mounting plate using standard DIN fasteners.

• Ensure plastic optical fiber (POF) cables maintain a minimum bending radius to prevent optical attenuation.

• Clean POF connector end-faces prior to inserting them into master or branch transceiver sockets.

• Push optical connectors firmly into place until mechanical snaps engage cleanly.

• Keep unused optical ports sealed with protective dust caps to prevent ambient dirt accumulation.

Technical Clarifications

• Does the NDBU-95 require external power input for optical signal splitting?

  Depending on the specific system configuration, internal active transceiver electronics derive operating power from connected master controller interfaces or external 24 VDC auxiliary loops.

• Can plastic optical fiber (POF) be interchanged with hard-clad silica (HCS) fiber on this unit?

  No. The transceivers on the NDBU-95 are specifically calibrated for plastic fiber optic (POF) cable attenuation and wavelength characteristics.

• What maximum number of drive channels can one NDBU-95 module serve?

  The unit features 9 individual branch channels, allowing a single master DDCS port to distribute signals to 9 separate follower drive units.

• Is live hot-swapping of fiber cables permitted on active DDCS networks?

  Unplugging active optical channels will disrupt drive communication loops, generating instant communication fault trips on the master controller.

• What primary transmission protocol does the NDBU-95 branching unit route?

  The unit routes high-speed DDCS (Distributed Drives Communication System) serial optical telegrams between master controllers and variable speed drives.

• How are field signal connections physically secured to the unit frame?

  Plastic optical fiber cables attach via snap-in optical connectors that plug directly into the board-mounted transmitter and receiver housings.

• What are the transport envelope specifications for the NDBU-95?

  The unit package measures 26.3 x 9.5 x 5.3 cm with an overall shipping weight of 0.7 kg.

• Does the unit require manual software or parameter configuration during replacement?

  No. The NDBU-95 acts as a hardware-level optical distribution node, requiring no local software parameter setup or IP address assignment.