ABB NTRO Series Modules NTRO02-A

Technical Dossier

Product Details And Specifications

ABB NTRO Series Technical Notes

The ABB NTRO series comprises digital and analog I/O termination units designed for use within ABB's S800 I/O system, which is the primary distributed I/O platform for the AC800M process automation controller family. Deployed across global heavy industry — including petrochemical refineries, nuclear power facilities, offshore platforms, and large-scale chemical processing plants — the S800 I/O system and its NTRO termination units represent one of the most widely installed DCS field interface architectures in continuous process industries. The NTRO termination units serve as the physical wiring interface between field instrumentation and the S800 I/O modules, providing screw-terminal or DSUB connectivity, signal conditioning rails, and module mounting positions on standard DIN rail or S800 I/O clusters. Their passive and semi-passive architecture means they have an exceptionally long service life, but sourcing replacements for aging installations requires specialist knowledge of ABB's part numbering conventions and hardware revisions.

The Evolution of NTRO Series Architecture

The NTRO termination unit family was introduced alongside the S800 I/O system in the mid-1990s as ABB transitioned its process automation portfolio from the older Master series (MOD 300, Advant OCS) to the AC800M / Symphony Plus platform. Early NTRO units were designed for direct rail mounting adjacent to S800 I/O modules such as the AI810, AO810, DI810, and DO810, providing a standardized field wiring interface that decoupled module replacement from field cable re-termination — a critical maintainability feature in live process environments.

Q: How are RFQ terms confirmed?
A: Quantity, required condition, documentation needs, destination and sourcing route are confirmed during RFQ review before quotation.

NTRO Series Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly encountered models within the ABB NTRO / S800 I/O termination unit ecosystem. Units are grouped by functional category.

Digital I/O Termination Units

• NTRO02-A: Digital I/O termination unit, screw-terminal field interface, DIN rail mount, S800 compatible
• NTRO01-A: Digital I/O termination unit, single-row screw terminal, standard channel density
• NTRO03-A: Digital I/O termination unit, extended channel configuration, S800 cluster mount
• NTRO04-A: Digital I/O termination unit with integrated fusing per channel, field-side protection
• NTRO05-A: Digital I/O termination unit, DSUB field connector variant, high-density wiring

Analog I/O Termination Units

• NTAI01-A: Analog input termination unit, 4–20 mA field interface, 8-channel, S800 AI810 compatible
• NTAI02-A: Analog input termination unit with HART signal pass-through, 8-channel
• NTAI03-A: Analog input termination unit, thermocouple/RTD signal interface, S800 AI820 compatible
• NTAO01-A: Analog output termination unit, 4–20 mA, 8-channel, S800 AO810 compatible
• NTAO02-A: Analog output termination unit with HART capability, 8-channel

Power & Bus Termination Units

• NTPS01-A: S800 I/O cluster power supply termination unit, 24 VDC field power distribution
• NTPS02-A: Redundant power supply termination unit, dual-feed field power, S800 cluster
• NTBU01-A: S800 I/O bus termination unit, ModuleBus end terminator, cluster configuration
• NTBU02-A: Extended bus termination unit, multi-cluster ModuleBus interface

Communication & Adapter Termination Units

• NTCI01-A: Communication interface termination unit, PROFIBUS DP field adapter, S800 compatible
• NTCI02-A: Communication interface termination unit, FOUNDATION Fieldbus H1 segment interface

Sourcing Hard-to-Find & Obsolete NTRO Series Parts

Q: How is condition confirmed before quotation?
A: Available condition, photos, test records and documentation are checked according to the requested model and sourcing channel before a formal RFQ response.