Schneider Electric ASS908022 Modicon S908 Remote I/O Processor Module

Description

The Schneider Electric ASS908022 is a high-performance Remote I/O Processor Module designed for the Modicon S908 network architecture. It serves as a critical communication bridge within Modicon 984 and Quantum PLC backplane systems, facilitating deterministic, real-time data exchange across distributed industrial environments. This module is engineered to support robust communication backbones in demanding sectors, including power generation, petrochemical processing, and heavy industrial mining, where signal reliability and low-latency data transmission are essential for operational continuity.

Features

• Dual-channel communication support for redundant coaxial cable paths (Channel A and Channel B).
• Automatic path switchover capability within a single scan cycle upon detection of line faults or signal attenuation.
• Galvanic isolation to protect sensitive backplane components from electromagnetic interference and voltage surges.
• Deterministic token-passing protocol management for consistent I/O scan timing.
• Supports up to 32 remote I/O drops on a single network segment.
• Designed for seamless integration into Quantum and 984 chassis backplane slots.

Applications

This module is optimized for large-scale distributed control systems requiring long-distance communication and high fault tolerance. It is commonly deployed in applications involving:

• Distributed I/O networks in thermal power plants.
• Remote terminal unit (RTU) coordination in mining and refining facilities.
• High-speed data acquisition across expansive manufacturing sites.
• Redundant network topologies requiring rapid recovery from cable failure.

Technical Specifications

Installation Guidelines

• Ensure the PLC backplane power is disconnected before installing or removing the module.
• Handle the module using proper ESD precautions to prevent damage to internal circuitry.
• Seat the module firmly into the designated chassis slot and secure the locking mechanisms.
• Use high-quality 75 Ohm coaxial cabling for all BNC connections; ensure cable shields are properly grounded to minimize noise.
• Verify that the dual-channel configuration is correctly mapped in the controller software to enable redundant path switching.
• Keep communication cables separated from high-voltage power lines to prevent EMI-induced transmission errors.

FAQ

What is the primary function of the ASS908022?
The module acts as a processor for the S908 network, managing the deterministic communication between the main controller and remote I/O stations over a coaxial bus.

Does this module support redundant communication?
Yes, it supports dual-channel (A and B) redundancy. If one cable path fails, the module automatically switches to the alternate path within one scan cycle.

What type of cable is required?
The module is designed for use with 75 Ohm RG-6 or RG-11 coaxial cables terminated with BNC connectors.