ABB NDBU-95C – Dual-bus communication module for Symphony/INFI 90 system reliability

The ABB NDBU-95C is a plug-in communication module designed for Symphony/INFI 90-based systems where redundant system bus connectivity is a must. From my experience, plants typically use it to keep controller communications stable under heavy traffic or when one bus leg has a fault. It seems to be a solid fit for upgrades and spares programs: drop it into the existing rack, connect the redundant bus lines, and you’re back to a predictable, low-latency link between controllers and nodes.

Typical use cases include recovering a node after bus errors, adding redundancy to an older cabinet before a shutdown, or replacing a failing board to clear intermittent communication alarms. One thing I appreciate is how straightforward it is for maintenance teams—minimal wiring changes, clear status indication, and compatibility with common Symphony/INFI 90 topologies.

Order Placement Process and Guarantees

• Warranty: 365 days
• Delivery: 1 week if in stock; no more than one month at the latest
• Payment: 50% advance payment; full payment before delivery
• Express options: FedEx, UPS, DHL

Key Features

• Dual-redundant bus channels – Maintains communications if one bus path is impaired; automatic switchover in most cases.
• Backplane-powered – No external power wiring; draws power from the Symphony/INFI 90 rack backplane for a clean install.
• Clear status & diagnostics – Front-panel indicators help technicians pinpoint link health and board status quickly.
• System-compatible design – Works within Symphony/INFI 90 architectures; typically pairs with standard controllers and node racks without special adaptors.
• Field-replaceable – Board swap can be done during a planned window; hot-swap is usually feasible in redundant systems when procedures are followed.
• Robust signaling – Redundant bus ports suited for legacy cabling media commonly seen in mature ABB DCS cabinets.

Technical Specifications

Related or Supporting Products

• ABB INNIS01 – INFI-NET to serial/network interface often used alongside bus modules for system interlinks.
• ABB INNPM12 – Network processing module; typically used for higher-level system communications and diagnostics.
• ABB BRC-100 / BRC-01 – Symphony/INFI 90 controllers that commonly reside on the same system bus as NDBU-95C.
• ABB NTAI05 / NTDI01 – Analog and digital I/O modules that depend on stable system bus communications.
• Earlier NDBU revisions (e.g., NDBU-95A/B) – In many cases functionally compatible; check firmware and connector details before mixing revisions.

Quick field note from a maintenance engineer we support: “Swapping to NDBU-95C cleared the bus fail intermittency on our east cabinet. Install took 15 minutes, and diagnostics were easier to read than our older board.”

Installation & Maintenance

• Environment – Mount in a clean, ventilated control cabinet. Keep ambient within the stated industrial range; avoid condensation and corrosive atmospheres.
• Cabinet & rack – Use standard Symphony/INFI 90 racks with intact card guides and grounding. Ensure proper spacing for airflow.
• Wiring – Use the specified bus cable type and impedance for your node (legacy systems often use matched coax). Maintain shield continuity and proper terminations.
• ESD handling – Wear a wrist strap, handle the board by edges, and de-energize per site procedures unless the system redundancy allows an on-line swap.
• Commissioning – Verify bus LED status, check redundancy switchover, confirm node visibility in the DCS, and archive the configuration/firmware info.
• Routine maintenance – Inspect connectors and terminations quarterly, clean dust with dry air, and log any transient bus errors for trending. Firmware baseline should be reviewed during shutdowns.
• Spares strategy – Keep at least one tested spare per cabinet cluster; it shortens recovery time for intermittent bus faults.

Quality & Certifications

• Certifications – CE (industrial EMC). UL recognition may vary by revision and region; verify label on the specific unit.
• RoHS – Legacy product status; exemptions may apply depending on production date.
• Manufacturing system – Produced under ISO 9001 quality management at the OEM level.
• Warranty – 12 months (365 days) from shipment as stated above.