TOSHIBA USIO21 Distributed I/O Controller Unit

The USIO21 is a distributed I/O controller unit for Toshiba NV‑Series DCS control system. It undertakes field signal acquisition and output drive tasks, and realizes high‑speed remote I/O communication via TC‑net I/O fault‑tolerant optical ring network. It acts as the key interface between system CPU and field‑site sensors and actuators.

This rack‑mount unit supports redundant optical ring communication, ECC memory error correction and hardware‑based IEC control logic execution. It is widely installed in power plant, petrochemical and metallurgy automation cabinets for field‑side distributed signal processing.

Main Specifications

• Brand: TOSHIBA; Model: USIO21; Series: NV‑Series DCS; Type: Distributed I/O Controller
• Field Bus: TC‑net I/O 100Mbps fault‑tolerant optical ring communication network
• Control Logic: Hardware accelerated IEC standard control language execution
• Reliability Feature: ECC memory error correction, supports redundant ring network configuration
• Network Port: Gigabit monitoring Ethernet port, optical ring transceiver interfaces
• Installation: Standard rack‑mount installation inside industrial control cabinet
• Power Supply: Industrial DC power input, meets power‑plant cabinet power‑supply requirements
• Operating Environment: ‑10℃ ~ +60℃, 5%‑95% RH non‑condensing, anti‑vibration industrial grade
• Diagnostic: Multi‑LED indicators for power, communication link and fault alarm status
• Certifications: CE, complies with heavy‑industry process‑automation equipment standards

Core Functions

• Collect field‑site digital and analog signals, transmit data to main CPU through TC‑net I/O optical fault‑tolerant ring network.
• Receive control commands from main controller, drive on‑site actuators, valves and interlock relay output equipment.
• Hardware‑accelerated logic processing ensures fast response for interlock protection and sequence control tasks.
• Fault‑tolerant optical ring design realizes communication link redundancy, avoiding single‑point network failure risk.
• ECC memory error detection and correction improves stability for long‑term continuous heavy‑duty industrial operation.
• On‑board LED status indicators help maintenance staff quickly locate communication, power‑supply and hardware faults.

Application Scenarios

• Spare‑part replacement for Toshiba NV‑Series DCS cabinets in thermal power plants, hydro‑power stations and petrochemical factories.
• Distributed field‑I/O control component for boiler, turbine auxiliary control and metallurgy process‑automation systems.
• Maintenance backup inventory for renovation and after‑sales maintenance projects of legacy Toshiba DCS control equipment.
• Matching I/O controller cooperating with NV‑series CPU modules, optical ring network and field‑site I/O terminal blocks.
• Retrofit replacement for old units suffering ring‑network interruption, signal acquisition deviation and hardware failure faults.
• Global aftermarket spare supply for automation maintenance teams maintaining Toshiba DCS‑system equipment worldwide.