Basic Information

• System Name: INFI 90 DCS
• Original Developer: Bailey Controls (Acquired by ABB in 1998)
• Release Year: Launched in 1988, upgraded successor of Network 90
• Product Category: Large-scale distributed process control system
• Successor Platform: Symphony Harmony / Symphony Plus

Core Technical Specifications

• Network Backbone: INFI-NET self-healing fiber optic ring network
  • Communication rate: 1 Mbps; maximum 250 nodes per ring
• Core Controller: MFC Multi-Function Controller (IMMFC02 / IMMFC03)
• Control Architecture: Fully distributed; control logic runs locally in Process Control Unit (PCU)
• Redundancy Support: Optional redundant controllers, redundant INFI-NET, redundant power supply
• I/O Capacity: Single system scalable up to 100,000 process I/O points
• Control Algorithms: Rich built-in function code library (PID, cascade, ratio, sequence logic, Smith predictor)
• Operating Temperature: 0 °C ~ +60 °C
• Storage Temperature: -40 °C ~ +85 °C
• Field Signal Support: 4–20mA analog, RTD, thermocouple, dry contact digital I/O; supports Modbus, HART via interface modules
• System Availability: Up to 99.999% with full redundant configuration
• 

Main System Composition

1. PCU (Process Control Unit)

   Rack assembly including MFC controller, INFI-NET interface modules (NPM, NIS), analog/digital I/O modules, system power supply.

   Common module series: IMDSI, IMDSO, IMASI, IMAO series I/O boards.

2. INFI-NET Communication Ring

   Fiber optic redundant ring connecting all PCUs, operator stations and gateways; automatic bypass upon single node failure.

3. Operator Workstation

   HMI for real-time monitoring, setpoint adjustment, alarm management, historical trending, configuration download.

4. Gateway & Interface Modules

   ICT computer interface, Modbus gateway, HART interface for connecting third-party instruments, PLCs and management systems.