Yokogawa A2NN30D-440000000 Node Interface Unit

The A2NN30D-440000000 is a NIU node interface unit for Yokogawa CENTUM VP N‑IO remote I/O system. This A2NN30D-440000000 acts as the bridge between FCU field control unit and N‑IO field I/O racks over N‑ESB bus, it also supplies 24VDC power to downstream N‑IO I/O modules. The A2NN30D-440000000 supports dual redundant communication and dual redundant power supply for high reliability in continuous process plants.

This A2NN30D-440000000 uses DIN rail mounting, supporting daisy-chain connection of multiple N‑IO base plates and I/O modules. It carries bus signal isolation, fault detection and bus status diagnostic functions, and front LEDs indicate power, link and fault status for quick troubleshooting. The suffix code 440000000 defines uplink bus type, hazardous area certification, mounting style and special order options for this variant. It pairs with A2BN3D / A2BN4D base plates and analog/digital I/O modules to build decentralized field I/O networks.

The A2NN30D-440000000 is widely used in chemical, oil & gas, power, pulp and water treatment DCS loops. The N‑IO series is a mature Yokogawa CENTUM VP remote I/O platform. Many instrument and maintenance teams stock the A2NN30D-440000000 as spare node interface unit for planned overhaul and emergency replacement of existing N‑IO stations.