Introduction

The Honeywell 2MLI-D24B Digital Input Module is a 32-point, 24 V DC source-type input module for the MasterLogic-200 PLC platform. It collects digital signals from field devices and makes their status available to the controller for equipment monitoring, process logic, and automated operation.

The module features photo-coupler isolation, configurable input response times, and LED status indication. Its 32-point configuration is useful in control systems where numerous discrete signals must be acquired without using multiple lower-density modules.

For maintenance engineers and system integrators, the 2MLI-D24B provides a dedicated digital input solution for compatible MasterLogic-200 installations. Verify the controller configuration, field-device wiring, and input requirements before installation or replacement.

Technical Specifications

Parameter	Specification
Brand	Honeywell
Model	2MLI-D24B
Product Type	Digital Input Module
PLC Series	MasterLogic-200
Number of Input Points	32
Input Type	24 V DC, source type
Rated Input Voltage	24 V DC
Operating Voltage Range	20.4–28.8 V DC
Maximum Ripple Rate	Below 5%
Rated Input Current	Approximately 4 mA
Input Resistance	Approximately 5.6 kΩ
ON-State Threshold	19 V DC or higher / 3 mA or higher
OFF-State Threshold	11 V DC or lower / 1.7 mA or lower
Response Time	Configurable: 1, 3, 5, 10, 20, 70, or 100 ms
Default Response Time	3 ms
Isolation Method	Photo-coupler
Isolation Voltage	AC 560 V RMS / 3 cycles
Isolation Resistance	10 MΩ or higher
Current Consumption	50 mA
External Connection	40-point connector
Dimensions	120 × 25 × 110 mm
Weight	0.10 kg / 0.22 lb

Recommended Related Models

Honeywell 2MLI-D21A Digital Input Module — An 8-point, 24 V DC input module for applications requiring fewer input channels.
Honeywell 2MLI-D22A Digital Input Module — A 16-point source/sink input module for compatible field circuits.
Honeywell 2MLI-D22B Digital Input Module — A 16-point source-type input module for compatible digital signals.
Honeywell 2MLI-D24A Digital Input Module — A 32-point source/sink input module for applications requiring a different input configuration.
Honeywell 2MLI-D28B Digital Input Module — A 64-point source-type input module for higher channel density.

Popular Related Models

Model	Product Description
Honeywell 2MLI-D21A	8-Point Digital Input Module
Honeywell 2MLI-D22A	16-Point Source/Sink Digital Input Module
Honeywell 2MLI-D22B	16-Point Source-Type Digital Input Module
Honeywell 2MLI-D24A	32-Point Source/Sink Digital Input Module
Honeywell 2MLI-D24B	32-Point Source-Type Digital Input Module
Honeywell 2MLI-D28A	64-Point Source/Sink Digital Input Module
Honeywell 2MLI-D28B	64-Point Source-Type Digital Input Module
Honeywell 2MLQ-TR4B	32-Point Source-Type Transistor Output Module

Applications

The Honeywell 2MLI-D24B Digital Input Module is a 32-point, 24 V DC source-type digital input module designed for the Honeywell MasterLogic-200 PLC platform. It receives discrete signals from field devices and transfers their status to the PLC for logic processing, equipment monitoring, and automated control.

With 32 input points, the module is suitable for applications that require multiple digital signals to be collected in a compact installation.

Typical applications include:

Machine automation: Monitoring limit switches, push buttons, and other discrete field signals.
Production lines: Collecting equipment status and interlock signals for automated sequences.
Industrial process monitoring: Detecting ON/OFF states from compatible field devices.
Equipment control: Providing input feedback for PLC-based control logic.
Control system maintenance: Replacing a compatible input module in an existing MasterLogic-200 installation.

Advantages

32 digital input points: Supports a high density of discrete input signals in one module.
24 V DC operation: Designed for common industrial control circuits.
Source-type input configuration: Supports compatible source-type field wiring.
Photo-coupler isolation: Provides electrical isolation between input signals and internal circuitry.
Adjustable response time: Allows input response settings to be configured through CPU parameters.
LED status indication: Helps technicians identify active input points during troubleshooting.
Compact modular design: Integrates into compatible MasterLogic-200 PLC systems.

Technical FAQs

Q1: What is the Honeywell 2MLI-D24B used for?

The 2MLI-D24B collects discrete 24 V DC signals from compatible field devices and sends their status to a MasterLogic-200 PLC for processing.

Q2: How many digital input points does it support?

The module supports 32 digital input points, with a common connection for the input group.

Q3: What is the rated input voltage?

The rated input voltage is 24 V DC. The documented operating range is 20.4–28.8 V DC, with a ripple rate below 5%.

Q4: What type of input circuit does the module use?

The 2MLI-D24B is a source-type digital input module. Confirm field-device output characteristics and wiring polarity before connecting external equipment.

Q5: What is the rated input current?

The rated input current is approximately 4 mA per input point.

Q6: Can the input response time be adjusted?

Yes. The response time can be configured to 1, 3, 5, 10, 20, 70, or 100 ms through CPU parameters. The default response time is 3 ms for both OFF-to-ON and ON-to-OFF transitions.

Q7: Does the module provide electrical isolation?

Yes. It uses photo-coupler isolation. The documented isolation voltage is AC 560 V RMS for three cycles under specified test conditions.

Q8: How can technicians check input status?

The module provides LED status indication. The corresponding LED turns on when an input is active.

Q9: What should be checked if an input signal is not detected?

Inspect the field device, 24 V DC supply, wiring polarity, common connection, and external connector. Check the input status indicators and confirm that the signal meets the module's ON-state voltage and current requirements.

Q10: Which module is suitable if more input channels are required?

The Honeywell 2MLI-D28B is a 64-point source-type digital input module for applications requiring additional input capacity. Confirm system compatibility and wiring requirements before selecting an alternative.

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