The Honeywell 621‑3580 Input Module is a high-density analog input module for Honeywell Distributed Control Systems (DCS). Featuring 32 individual 24 V DC sink inputs, this module is tailored to manage large numbers of field signals—ideal for industrial automation, manufacturing processes, and safety-critical monitoring.

Key Features

• 32 sink-type 24 V DC inputs for extensive signal acquisition

• High-density design optimizes rack space

• Built-in fault detection and channel diagnostics

• Galvanic isolation safeguards against ground loops

• Designed for DIN‑rail or rack mounting

• Hot-swappable capability—no system shutdown for servicing

• Rugged construction withstands industrial noise and temperature variations

Technical Specifications

Industry Applications

• Manufacturing Automation – Monitoring multiple sensors in production lines

• Power & Energy – Tracking digital signals in substation and turbine control systems

• Oil & Gas & Petrochemical – Safety alarms, valve signals, status indicators

• Water & Wastewater – Supervisory signals from pumps, level switches

• Process Industries – Comprehensive monitoring of boiler, reactor, filtration systems

Product Advantages

• High Channel Density – 32 inputs in a compact form factor reduce installation footprint

• Reliable Isolation & Diagnostics – Per-channel protection and early fault alerts enhance system robustness

• Ease of Maintenance – Hot-swappable design eliminates downtime during service

• Flexible Integration – DIN-rail and rack-compatible; Modbus enables seamless connectivity

• Industrial Robustness – Wide temperature tolerance suits demanding environments

Frequently Asked Questions (FAQ)

1. How many inputs does the 621‑3580 support?

   It provides 32 sink‑type digital input channels at 24 V DC.

2. What is a sink input?

   Sink inputs complete the circuit by sourcing current from the field device to the module’s internal 24 V supply.

3. Does the module include diagnostics?

   Yes, it offers channel‑level fault detection (open circuit/short).

4. What is the operating temperature range?

   –40 °C to +85 °C.

5. Can I service this without shutting down the system?

   Yes, it supports hot‑swapping.

6. What communication protocol does it use?

   Modbus RTU is typical .

7. What size is the module?

   Approximately 120 × 80 × 50 mm.

8. Is it isolated per channel?

   Yes, with galvanic isolation for safe operation.

9. Where is it typically used?

   In systems requiring many high-speed, reliable digital inputs—like manufacturing and process plants.

10. Is it compatible with standard Honeywell racks?

    Yes, it fits the 620/621 series rack or DIN‑rail frames.