Introduction

The Honeywell 2MLQ-TR8B is designed for situations where a PLC system needs a substantial number of digital output channels without creating an unnecessarily large I/O footprint. Its 64-point transistor output architecture provides a high-density solution for MasterLogic-200 control systems.

The most important characteristic distinguishing the 2MLQ-TR8B from the corresponding 2MLQ-TR8A is its source-type output configuration. This allows engineers to select the output architecture that best matches the electrical design of the field devices and control cabinet.

Transistor switching is well suited to automated equipment where outputs may be switched repeatedly during normal machine operation. Compared with mechanical relay contacts, semiconductor switching provides a fast response and avoids mechanical contact wear, making it valuable for many high-cycle DC control applications.

The module also incorporates photo-coupler isolation, a Zener-diode surge absorber, LED output indication, and a response time of 1 ms or less. Together, these features make the 2MLQ-TR8B a capable component for demanding multi-channel automation systems.

For system integrators, machine builders, and maintenance engineers, the module provides a practical way to expand discrete output capacity while maintaining a clean and structured MasterLogic-200 I/O configuration.

Technical Specifications

Parameter	Specification
Brand	Honeywell
Model	2MLQ-TR8B
Product Type	Transistor Output Module
PLC Platform	MasterLogic-200
Output Type	Digital Transistor Output
Output Configuration	Source Type
Number of Output Points	64
Isolation Method	Photo Coupler Isolation
Rated Load Voltage	DC 12/24 V
Load Voltage Range	DC 10.2–26.4 V
Maximum Load Current	0.1 A / Point
Maximum Common Current	2 A / COM
Off Leakage Current	0.1 mA or less
Maximum Inrush Current	4 A / 10 ms or less
Maximum ON Voltage Drop	DC 0.3 V or less
Surge Absorber	Zener Diode
OFF → ON Response Time	1 ms or less
ON → OFF Response Time	1 ms or less
Common Method	32 Points / 1 COM
Current Consumption	230 mA with all points ON
External Power Supply	DC 12/24 V ±10%
External Supply Ripple	4 Vp-p or less
External Supply Current	10 mA or less at DC 24 V connection
Operation Indicator	LED
External Connection	40-Pin Connector × 2
Suitable Cable Size	0.3 mm²
Dimensions	114 × 48 × 127 mm
Weight	0.15 kg (0.33 lb)

Recommended Related Models

Model	Product Type	Typical Role
Honeywell 2MLQ-TR8A	Transistor Output Module	64-point sink-type transistor output
Honeywell 2MLQ-TR4B	Transistor Output Module	32-point source-type transistor output
Honeywell 2MLQ-TR4A	Transistor Output Module	32-point sink-type transistor output
Honeywell 2MLQ-TR2B	Transistor Output Module	16-point source-type transistor output
Honeywell 2MLQ-TR2A	Transistor Output Module	16-point sink-type transistor output
Honeywell 2MLQ-RY2A	Relay Output Module	Alternative relay-based digital output

Popular Related Models

Model	Product Type
Honeywell 2MLI-D28A	64-Point Digital Input Module
Honeywell 2MLI-D28B	64-Point Digital Input Module
Honeywell 2MLI-D24A	32-Point Digital Input Module
Honeywell 2MLI-D24B	32-Point Digital Input Module
Honeywell 2MLQ-TR8A	64-Point Transistor Output Module
Honeywell 2MLQ-TR4A	32-Point Transistor Output Module
Honeywell 2MLQ-TR4B	32-Point Transistor Output Module
Honeywell 2MLQ-TR2A	16-Point Transistor Output Module
Honeywell 2MLQ-TR2B	16-Point Transistor Output Module

Applications

The 2MLQ-TR8B is suited to control systems that require numerous DC output signals and a source-type transistor configuration.

Automated production machinery – Controls compatible solenoids, actuators, indicators, and auxiliary control circuits.
Assembly equipment – Provides multiple output commands for sequential machine operations.
Packaging machinery – Handles repetitive switching signals for actuators, valves, and machine mechanisms.
Conveyor systems – Controls compatible DC devices used for conveying, sorting, diverting, and positioning.
Material-handling equipment – Supports coordinated output control for automated transfer and handling processes.
Factory automation panels – Adds 64 digital output points while keeping the I/O structure compact.
OEM machine control – Offers a high-density output solution for machine builders working with MasterLogic-200.
PLC expansion projects – Provides additional transistor output capacity when an existing control system requires more discrete outputs.

The source-type architecture makes correct field-device selection and wiring especially important during system engineering.

Key Strengths for Control Engineers

64-point high-density output
The 2MLQ-TR8B provides 64 transistor output channels in one module. This high channel count can simplify I/O planning when a machine or process contains a large number of discrete control points.

Source-type transistor outputs
Unlike the sink-type 2MLQ-TR8A, the 2MLQ-TR8B uses a source output configuration. This distinction is important when matching the module to field-device wiring and the overall DC control architecture.

Fast switching performance
The specified response time is 1 ms or less for both OFF-to-ON and ON-to-OFF operation under the applicable conditions. This makes the module suitable for many repetitive and sequence-based automation tasks.

Broad DC operating range
The rated load voltage is DC 12/24 V, with a specified load-voltage range of DC 10.2–26.4 V. This supports common industrial DC control arrangements.

Photo-coupler isolation
Photo-coupler isolation provides electrical separation within the I/O circuit and helps support dependable operation in industrial control environments.

Built-in surge protection
The output circuitry incorporates a Zener-diode surge absorber, adding protection against applicable transient conditions.

Efficient cabinet utilization
A 64-point output capacity in a compact module makes the 2MLQ-TR8B particularly attractive for control cabinets where available installation space is limited.

Easy output-status observation
LED indication gives commissioning and maintenance personnel a convenient way to monitor output operation while troubleshooting field circuits.

Technical FAQs

1. What type of output module is the Honeywell 2MLQ-TR8B?
The 2MLQ-TR8B is a 64-point digital transistor output module with a source-type output configuration for the Honeywell MasterLogic-200 PLC system.

2. What is the difference between the 2MLQ-TR8A and 2MLQ-TR8B?
Both modules provide 64 transistor output points, but the 2MLQ-TR8A is a sink-type output module, while the 2MLQ-TR8B is a source-type output module. The correct selection depends on the electrical arrangement of the connected field devices.

3. What voltage can be applied to the output load circuit?
The rated load voltage is DC 12/24 V, with a specified load-voltage range of DC 10.2–26.4 V.

4. What is the maximum output current per point?
Each output point supports up to 0.1 A, while the maximum current is 2 A per COM. The field loads must be selected accordingly.

5. What is the maximum permissible inrush current?
The specified maximum inrush current is 4 A for 10 ms or less. Loads with higher or longer-duration inrush characteristics require an appropriate external interface rather than direct connection to the output.

6. How quickly does an output channel respond?
The OFF-to-ON response time is 1 ms or less, and the ON-to-OFF response time is also 1 ms or less under the specified rated-load, resistive-load condition.

7. What is the maximum ON-state voltage drop?
The maximum specified voltage drop in the ON state is DC 0.3 V or less.

8. How are the 64 output points grouped?
The module uses a 32-point / 1 COM grouping arrangement. The two output groups therefore have separate common connections that should be wired according to the module's source-output circuit configuration.

9. What should be checked if a connected actuator does not operate?
Confirm the PLC output command first, then check the corresponding LED indication, external DC supply, source-output wiring, common connection, polarity, field wiring, and load condition. This helps determine whether the problem is related to the control program, I/O module, wiring, or field device.

10. Can the 2MLQ-TR8B be used for AC loads?
The module is designed for DC 12/24 V loads and should not be treated as a general-purpose AC output module. AC loads should be controlled through an appropriate interface or a module specifically designed for AC switching.

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