Product Overview

The Honeywell MLI-DR20SU serves as a high-density, versatile I/O solution within the MasterLogic-50 PLC ecosystem. Designed for space-critical applications, this "Combo" module integrates 12 digital inputs and 8 robust relay outputs into a single, streamlined chassis. It excels in small-to-medium scale automation tasks where reliable signal acquisition from field sensors and direct control of high-current actuators—such as solenoids, motor contactors, and alarm indicators—are required. By consolidating I/O functions, the MLI-DR20SU reduces cabinet footprint while maintaining the high industrial-grade reliability expected of Honeywell systems, performing flawlessly in electrically noisy and thermally demanding environments.

Hybrid Architecture & Integrated Communication

The MLI-DR20SU utilizes a sophisticated hybrid hardware architecture that bridges field-level signals with logic processing. The input stage features opto-isolation to protect internal circuitry from voltage spikes, while the output stage employs high-capacity relays capable of switching up to 2A.

Beyond standard I/O processing, this module integrates dual-interface communication (RS-232 and RS-485). This allows the MLI-DR20SU to function as a localized control node or a distributed I/O gateway. It strictly adheres to IEC 61131-3 standards, enabling engineers to deploy logic via Ladder Diagram (LD) or Function Block Diagram (FBD) with zero compatibility friction. The built-in noise filtering algorithms ensure that input signal debounce times are managed at the hardware level, providing clean data to the CPU even in high-EMI settings.

Core Technical Specifications

Field Engineering & Installation Guide

Optimal performance of the MLI-DR20SU depends on proper electrical termination and thermal management. Ensure that 24VDC input wiring is shielded and routed away from high-voltage AC power lines to minimize induced noise. For the relay outputs, we recommend installing external surge suppressors (snubber circuits or flyback diodes) when switching inductive loads like large solenoids to extend the mechanical life of the internal relays.

The module supports DIN-rail mounting. Maintain at least 20mm of clearance above and below the unit for natural convection cooling. When utilizing the RS-485 serial port for networking, ensure the bus is terminated with a 120-ohm resistor at the furthest node to prevent signal reflection and data corruption.

Industrial Integration Advantages

The MLI-DR20SU is purpose-built for the rigors of modern industrial control. Its dual-voltage relay capacity (AC/DC) provides engineers with the flexibility to drive diverse field equipment without adding interposing relays, directly lowering the Bill of Materials (BOM) cost. Its seamless integration with the MasterLogic-50 series ensures that it can be hot-swapped or expanded within an existing DCS framework, such as Honeywell Experion, providing a scalable path for facility upgrades. The conformal protection on the PCB assembly guarantees stable operation in environments with non-condensing humidity and airborne particulates.

Delivery Information

Delivery time: 3-5 days when payment finish, BY DHL/FEDEX/UPS.

All modules are shipped in anti-static industrial packaging and original Honeywell factory-sealed boxes to ensure the unit arrives in pristine, ready-to-install condition.

Technical FAQs

Q1: Can the relay outputs on the MLI-DR20SU handle 220VAC directly?

A1: Yes, the integrated relays are rated for up to 2A at 220VAC. However, for highly inductive loads, external fusing and surge protection are recommended to protect the module’s internal contact points.

Q2: What is the primary difference between the RS-232 and RS-485 ports on this module?

A2: The RS-232 port is typically used for point-to-point configuration and local programming, while the RS-485 port is designed for multi-drop networking over longer distances (up to 1.2km) within an automation bus.

Q3: Does the module require a separate power supply for the digital inputs?

A3: The input section operates on standard 24VDC. While the module derives logic power from the PLC backplane, the field-side sensors typically require an external 24VDC supply to complete the input loop.

Q4: Is this module compatible with other MasterLogic series PLCs?

A4: The MLI-DR20SU is specifically optimized for the MasterLogic-50 series. For integration with MasterLogic-200 or 1400 systems, verify backplane compatibility and protocol mapping via Honeywell SoftMaster software.