ABB Bailey INFI 90 INNIS21 and the communication mechanism of INFI-NET high-speed ring network. INNIS21 is a dedicated Network Interface Module (NIS) in the INFI 90 system. Its main task is to seamlessly connect the control stations (such as PCU/BRC controllers and various I/O modules) to the INFI-NET high-speed ring network. Below is a layered analysis of its working principles and key points.

What is the working principle and key points of ABB Bailey INFI 90 INNIS21?

1. Hardware and Physical Layer Ring Network Dual-Channels Interface: The board is equipped with two optical fiber or coaxial ports (depending on the field selection), serving as the primary and backup channels respectively. Redundant Topology: The two channels form a closed loop (Ring); in the event of any single point failure, data automatically detours in the opposite direction, achieving network self-healing. Industrial-grade Transceiver Circuits: Provide isolation and anti-interference capabilities, ensuring stable operation in strong electromagnetic environments such as power and chemical industries.

2. Data Link Layer INFI-NET Dedicated Protocol: Based on a token-passing mechanism. Only the node holding the token can send data, preventing collisions. The token circulates within the ring, ensuring real-time performance and determinism. Node Addressing: Each INNIS21 module is assigned a unique node number through DIP switches or configuration software for network routing and arbitration.

3. Upper Layer Communication and Gateway Functions Data Buffering and Queue Management: The internal CPU and memory of INNIS21 buffer the data sent/received from the control station, balancing the load of tasks with different rates. Message Formatting: Encapsulates the data frames from the internal bus of the controller (Bailey Control Bus) into INFI-NET frames and then decodes them back to the local bus format, enabling bidirectional conversion. Time Synchronization: Can receive synchronization information from the master clock, ensuring that timestamps of events across the network are consistent.

4. System Integration and Redundancy Primary/Backup Network Redundancy: Two INNIS21 modules can be configured as A/B channels or primary/backup nodes, enabling automatic switching. Online Diagnostics: Onboard LEDs and system self-check (Watch-dog) provide real-time indications of link status and node health. Hot-Swap Maintenance: Supports module replacement during ring network operation without interrupting communication.

5. Actual Communication Bridge Process Example Collection: Lower-level controllers send real-time data to INNIS21 via the backplane bus. Encapsulation and Queueing: INNIS21 encapsulates the data into INFI-NET frames and waits for the token. Token Acquisition: Once the token arrives, the module sends frames along the ring network. Routing and Forwarding: The target node receives and verifies, forwarding to the operation station or upper systems if necessary. Return Path: Responses or commands are transmitted back to the controller using the same mechanism.

ABB Bailey INFI 90 INNIS21 Advantages Overview

1.High Reliability and RedundancyDual-ring structure: Automatic switching between main/backup links ensures communication is maintained even if a segment of the ring network is interrupted.Token Ring protocol: Ensures orderly data transmission to avoid collisions, suitable for critical process control.Self-diagnosis and fault indication: Onboard LEDs and system self-checks help quickly locate problems, reducing downtime risks.
2.Excellent Real-time Communication PerformanceHigh-speed transmission: Supports INFI-NET bandwidth of over 1 Mbps, meeting the real-time exchange of large-scale process data in power, chemical, and other industries.Deterministic timing: The token-passing mechanism ensures fixed response times, suitable for delay-sensitive control loops.Time synchronization: Can receive system clock signals to achieve consistent event timestamps across the network.
3.Compatibility and ExpandabilityBackward compatibility: Interconnects with earlier Bailey Network 90 and ABB Symphony systems, facilitating upgrades of older systems.Modular design: Directly plugs into standard INFI 90 racks, making system expansion or function adjustments easy.Hot-swappable: Maintenance or replacement can be done without downtime, ensuring production continuity.
4.Industrial-grade DurabilityWide temperature and anti-interference: Meets the harsh environmental requirements of power plants, petrochemical, metallurgy, and other industries.Long-life components: Suitable for long-term 7×24 hour operation, reducing total lifecycle costs.

Summary

INNIS21 serves as a true "communication bridge" between the physical layer, link layer, and upper application layer through hardware dual-ring ports, token ring protocols, and data encapsulation conversion. It ensures high-reliability, low-latency, and redundant fault-tolerant real-time data interaction between INFI 90 control stations and the INFI-NET high-speed ring network, providing a stable DCS communication backbone for continuous processes such as power and petrochemicals.