ABB

ABB Bailey NTRO02‑A Relay Output Termination Printed‑Circuit‑Board

Warranty： 365 days
Quality: Original module
Condition： New / Used
Warehouse: Spot
Delivery time: Shipped in 3 days after payment
Mailbox：plcvarious@foxmail.com

+086 18205988494

Introduction

Main Functions

Field‑side Signal Termination & Relay Isolation Output It is the field‑wiring termination board for DCS digital output signals. It receives logic‑level control signals from DCS I/O modules, drives on‑board electromagnetic relays and provides dry‑contact relay outputs for field devices. It realizes galvanic isolation between DCS internal control circuit and field‑side load circuits to suppress surge, ground‑loop noise and prevent interference from feeding back into DCS main rack.
Multi‑channel Discrete Signal Routing Provides screw terminal blocks for convenient field cable connection. Routes DCS output commands to on‑board relay coils, and distributes relay dry‑contact switching signals to field actuators. Supports both AC and DC field loads via relay contact outputs.
Hardware Protection & Channel‑level Status Indication Integrates surge‑absorbing components for over‑voltage and transient‑surge protection. Each channel is equipped with LED indicator lamps to show relay on‑off status for on‑site visual troubleshooting. It provides channel‑to‑channel and channel‑to‑ground electrical isolation.
Back‑plane Interface Matching Connects to DCS I/O modules via dedicated flat‑cable connector. It does not contain main control logic; it only executes signal switching and termination functions, powered by external field‑side power for relay contacts.
Cabinet‑mount Industrial Hardware Design Designed for installation inside control cabinet or termination rack. It works cooperatively with INFI‑90 block I/O hardware. It cannot run independently without matching DCS output modules.

Note: NTRO02‑A is EOL (End‑of‑Life / Obsolete) legacy spare PCB assembly. Original OEM mass‑production is discontinued. It serves purely as termination‑relay board and cannot perform control logic computation by itself.

ABB Bailey NTRO02‑A Relay Output Termination Printed‑Circuit‑Board

Applications

This relay output termination board is dedicated spare hardware for legacy ABB Bailey INFI‑90 / Symphony Harmony DCS distributed control systems:

Thermal power plants: Drive solenoid valves, fan / pump interlock circuits, alarm beacons, and local indicator lamps for boiler‑turbine auxiliary control system.
Petrochemical & chemical industry: Execute discrete interlock and shutdown‑loop output for reactors and distillation units, control field‑site valves and actuators.
Pulp‑paper, metallurgy and large‑scale water‑waste‑water facilities: Realize on‑off control for pumps, dosing valves and safety interlock equipment.
Industrial maintenance & retrofit: Direct replacement for defective NTRO02‑A termination board on existing INFI‑90 DCS systems, restore isolated relay output and field‑wiring termination functions for discrete control loops.