HONEYWELL MLC-DN64H/DC Digital Output Power Supply Module

The HONEYWELL MLC-DN64H/DC is a high-performance combined Digital Output Power Supply Module engineered for MasterLogic PLC and DCS architectures. This versatile component delivers localized internal module power conversion while simultaneously operating a high-density, high-speed digital output interface designed to control field devices with precise determinism.

Hardware Specifications

Process Control & DCS Integration

The MLC-DN64H/DC bridges power distribution and discrete sequence execution within a single physical footprint. It handles 32 high-current sinking outputs, using photo-coupler isolation barriers to protect sensitive backplane microprocessors from field-side electrical transients or inductive feedback loops.

The module supports diverse scanning topologies to optimize control loops based on application urgency:

• Repetitive Scan & Cyclic Scan: Standard sequential execution profiles for basic logic loops.
• Interrupt Scan & Constant Scan: Fixed-interval processing modes for precise timing dependencies.

Its internal processing core runs at an ultra-fast speed of 83 nanoseconds per basic instruction step. It natively supports a command matrix containing 28 basic and 687 applied instructions configured via Ladder Diagram (LD) and Instruction List (IL) programming languages.

Frequently Asked Questions

Q: How does a sinking digital output loop behave electrically on this module?

A: In a sinking configuration, the module’s internal solid-state switch connects the field device load to the negative return path (DC Common). The external 24 VDC supply must be fed directly to the load terminal first.

Q: Is this module capable of driving heavy inductive loads like large solenoid valves?

A: Yes. Each point supports up to 0.5A and features integrated Zener diode surge suppression. However, for highly repetitive inductive switching or loads near the 0.5A threshold, installing an external flyback diode across the load is highly recommended to minimize localized heat generation.

Q: Can this power supply drive external field transmitters?

A: No. The primary 100-240 VAC supply input powers the module’s internal logic and backplane rail architecture. Field devices driven by the 32 digital output channels must be energized using a separate, external 24 VDC power loop.

Field Installation Guidelines

1. Confirm that the main rack AC source breaker is switched off before mounting or extracting the module.
2. Align the card layout tabs with the designated slot guide rails and push firmly until the backplane multi-pin bridge clips lock into place.
3. Wire the 100-240 VAC line, neutral, and physical earth ground to the dedicated power terminals, verifying correct ground continuity to the chassis.
4. Route field digital output wires separately from high-voltage motor starters to preserve low electrical noise thresholds.