Digital guide
You are here:
Schneider Electric AS-J890-101-1004
Product Name
Modicon remote I/O processor / RIO head module.
Overview
Remote I/O communication processor for distributed Modicon I/O architectures. It connects a main PLC processor or RIO scanner to remote I/O drops over coaxial network and manages data exchange between control processor and field I/O.
Detailed content
Technical Specifications
- Module type: Remote I/O processor / RIO head
- Compatible architecture: Modicon 800-series RIO documentation; some distributors also list Quantum/generic RIO use
- Network protocol: Modicon Remote I/O
- Data rate: 1.54 Mbps
- Cable type: RG-11/U coaxial, 93 ohm
- Connectors: dual BNC, Channel A and Channel B
- Maximum drop distance: 457 m / 1500 ft per drop at 1.54 Mbps
- Maximum drops per channel: 31
- Power consumption: approximately 3.5 W
- Indicators: communication, error, power LEDs
- Backplane: Modicon 800-series RIO rack documentation
Functional Features
Dual-channel BNC interface for main/alternate cabling, RIO polling management, drop addressing through hardware/configuration, fault and activity LED diagnostics, replacement compatibility with several AS-J890 revisions per distributor cross-reference.
Application Scenarios
Discrete manufacturing lines, legacy Modicon retrofit, remote motor control centers, distributed sensor/actuator panels, plants retaining 800-series I/O while upgrading processor communications.
Material Composition
Industrial plastic/metal front bezel, multilayer PCB, BNC coaxial connectors, LED lenses, rack-edge grounding contacts.
Structural Characteristics
RIO processor card format for Modicon rack slot, dual BNC front connectors, backplane pin interface, LED status cluster.
Working Principle
The processor receives RIO poll commands from the master scanner, addresses each remote drop through the coaxial network, collects input data and returns output commands in deterministic RIO cycles. BNC Channel A/B allows segmented or redundant cable paths within the configured RIO topology.
Installation Requirements
Install in the designated RIO processor slot of the compatible Modicon rack. Use 93-ohm RG-11 coaxial cable with proper BNC termination. Set drop/node parameters according to system architecture. Verify terminators at both ends of each channel. Ground the rack and shield according to Modicon RIO wiring practice.
Usage Precautions
Confirm 1.54 Mbps versus legacy 574 kbps modules before mixing. Do not operate with missing coaxial terminators. Check BNC continuity after cable modification. Replace with identical or documented-compatible firmware revision to avoid I/O mapping changes.
