Product Description

Model Number Interpretation

• 404: Core series identifier for Reliance’s high‑density digital I/O modules, targeted at AutoMax distributed control systems.

• T: Indicates Terminal block interface for field wiring.

• SD: Denotes Sink/Source input type compatibility (24 VDC wet contact or dry contact).

Technical Specifications

• Channel Count: 32 isolated digital input channels.

• Input Voltage: 24 VDC (operating range: 15–30 VDC).

• Input Current: 3.5 mA typical at 24 VDC.

• Response Time: <10 ms (configurable hardware filtering).

• Isolation: Group‑wise optical isolation (8 channels per group); field‑to‑system isolation.

• Operating Temperature: 0 °C to +60 °C.

• Storage Temperature: ‑40 °C to +85 °C.

• Humidity: 5%–90% non‑condensing.

• LED Indicators: Per‑channel ON/OFF status; module OK/fault LED.

• Mounting: Standard AutoMax S‑RACK I/O rack (backplane‑mounted).

• Hot‑Swap: Supported (system‑configuration dependent).

• Protection Rating: IP20 (for cabinet installation).

Interface & Communication Configuration

• Field Interface: Screw‑terminal block for direct connection to dry contacts (limit switches, pushbuttons) or 24 VDC wet contacts (sensors, relays).

• Backplane Interface: AutoMax proprietary backplane bus for high‑speed communication with the main processor (e.g., 57C331 CPU).

• Communication Protocol: No native Ethernet; relies on backplane bus for data exchange with the AutoMax DCS network.

• Diagnostic Interface: Front‑panel LED indicators for channel status and module health; no external diagnostic port.

Core Functions

• High‑Density Signal Acquisition: Captures 32 discrete on/off signals from field devices, converting them to logic‑level data for the controller.

• Fault Isolation: Group‑wise isolation limits short‑circuit impacts to 8 channels, preventing system‑wide failures.

• Noise Filtering: Configurable hardware filtering suppresses contact bounce and electrical interference for stable signal readings.

• Status Monitoring: Per‑channel LEDs enable quick visual verification of input states; module OK LED confirms healthy operation.

• Legacy System Integration: Seamlessly integrates with AutoMax programming software (Logic Builder/System Manager) for automatic address mapping and logic access.

Application Scenarios

• Legacy AutoMax DCS Systems: Primary digital input module for Reliance AutoMax platforms in power plants, water treatment facilities, and manufacturing sites.

• Heavy Industry: Steel mills, paper mills, and chemical plants for monitoring valve positions, motor status, and safety interlocks.

• Process Automation: Conveyor systems, packaging machinery, and assembly lines requiring high‑density discrete signal monitoring.

• Legacy Equipment Maintenance: Direct replacement for aging S‑D4043/404TSD modules to extend the service life of AutoMax systems.

Usage & Maintenance Instructions

• Installation: Insert into a designated slot in the AutoMax S‑RACK; ensure the backplane connector is fully seated and secured with rack screws.

• Wiring: Connect field devices to the screw terminals per the system schematic; verify wiring polarity and tightness to avoid loose connections.

• Configuration: Use AutoMax programming software to assign input addresses and configure filtering parameters; download the configuration to the module.

• Operation: Apply power and verify the module OK LED is lit; check per‑channel LEDs for correct input status during normal operation.

• Routine Maintenance: Quarterly inspections to clean dust from the module surface and terminals; verify LED functionality and backplane connection integrity.

• Safety: Disconnect all power to the rack before installation/removal; discharge capacitors fully to prevent electric shock. Adhere to lockout/tagout procedures during maintenance.