Honeywell 2MLQ-TR4A Transistor Output Module

Applications

The 2MLQ-TR4A can be integrated into a wide range of PLC-controlled industrial systems where multiple DC output signals need to be switched reliably.

• Machine automation: Controls solenoids, actuators, signal lamps, contactor interfaces, and other discrete devices.
• Production lines: Provides multiple output channels for sequential machine operations and automated production processes.
• Material handling: Suitable for conveyor control, sorting mechanisms, pneumatic components, and automated handling equipment.
• Packaging equipment: Supports repetitive switching operations used in filling, labeling, sealing, and packaging machinery.
• Assembly systems: Controls individual machine stations and coordinated actuator sequences.
• Process auxiliary systems: Can operate compatible DC valves, alarms, indicators, and auxiliary control devices.
• Industrial control panels: Offers 32 transistor output points where a high-density I/O arrangement is preferred.
• MasterLogic-200 system expansion: Provides additional digital output capacity for existing PLC installations.

The 2MLQ-TR4A is especially attractive for systems that require fast and repetitive DC switching rather than the mechanical switching characteristics of relay outputs.

Advantages for Industrial Automation

32-point output density
With 32 transistor output channels in one module, the 2MLQ-TR4A helps engineers manage a large number of discrete devices while keeping the I/O architecture organized and compact.

Fast transistor switching
Transistor technology provides a fast response suitable for repetitive machine operations, sequencing, and applications where output timing is important.

Sink-type output design
The sinking output configuration provides a clear and established wiring approach for compatible DC field devices. Proper matching between the module, external supply, and load is essential for dependable operation.

DC 12/24 V compatibility
The module is designed for commonly used industrial DC control voltages, making it suitable for many 12 VDC and 24 VDC field-control applications.

Electrical isolation
Photo-coupler isolation helps separate the output circuitry from the PLC control side, supporting more robust operation in an industrial electrical environment.

Low-voltage output drop
The transistor output design maintains a low ON-state voltage drop, helping provide efficient switching for appropriate loads.

Useful diagnostic indication
Output status LEDs allow technicians to quickly check whether individual output channels are being commanded during commissioning and maintenance.

Compact engineering solution
The combination of 32 channels and a compact module format makes the 2MLQ-TR4A a strong option for control cabinets where efficient use of installation space matters.

Technical FAQs

1. What type of output does the Honeywell 2MLQ-TR4A provide?
The 2MLQ-TR4A is a digital transistor output module with a sink-type output configuration. The external wiring must therefore be designed according to the sinking-output circuit arrangement.

2. How many output channels are available?
The module provides 32 transistor output points, allowing a single module to control a relatively large number of compatible DC field devices.

3. What field voltage is supported by the output circuit?
The rated load voltage is DC 12/24 V, with an operating load-voltage range suitable for common industrial DC control systems.

4. What is the maximum current for each output point?
Each output point supports a maximum load current of approximately 0.1 A. The connected load should remain within the specified electrical limits.

5. What is the maximum current allowed through the common connection?
The common circuit is designed for a maximum current of approximately 2 A per COM group. Load distribution should be considered when several channels operate simultaneously.

6. How fast can the outputs switch?
The specified output response is approximately 1 ms or less for both OFF-to-ON and ON-to-OFF operation under the applicable test conditions. This makes the module appropriate for many fast repetitive control sequences.

7. Does the 2MLQ-TR4A use relay contacts?
No. It uses semiconductor transistor outputs rather than mechanical relay contacts. This makes it more suitable for rapid and repetitive DC switching applications.

8. How should a faulty output channel be diagnosed?
Start by checking the PLC program status and corresponding output LED. Then verify the field supply, common connection, wiring continuity, load condition, and output voltage. Comparing the commanded PLC state with the physical output condition can help isolate whether the problem originates in the program, module, wiring, or field device.

9. Can the module directly control any DC load?
No. The connected device must meet the module's voltage, current, switching, and output configuration requirements. Loads exceeding the specified current capacity should not be connected directly to an output point.

10. Why is correct sink-output wiring important?
Because the 2MLQ-TR4A uses a sinking transistor configuration, the external power supply and load must be connected in the correct polarity and circuit arrangement. Incorrect wiring can prevent the field device from operating properly and may create an electrical fault.