Our advantage
Global Logistics
We have a 10-year logistics and express cooperation agreement, so our products can be shipped to any place in the world.
Brand new and original
Our products are imported in bulk from the place of origin. Because of the cooperative relationship, our products are all original and 100% new.
24-hour service
We provide 7*24 hours service to our customers. We will be there whenever you need us.
Price advantage
All our products are priced very favorably because we have our own warehouse and supply.
| Company Information | |||
| [email protected] | |||
| Mobile | +8615980777398 | ||
| +8615980777398 | |||
| 15980777398 |

The Honeywell 2MLQ-TR4B is a 32-point transistor output module for the MasterLogic-200 PLC system. It uses a sourcing (PNP) output configuration to switch external DC loads, making it suitable for industrial control circuits involving solenoid valves, indicator lamps, auxiliary relays, and other compatible field devices.
An important distinction between the 2MLQ-TR4B and the closely related 2MLQ-TR4A is the output polarity. The TR4B supplies current from the positive DC side when an output is activated, whereas the TR4A uses a sinking configuration. This difference directly affects field wiring and load compatibility, so the two models should not be treated as electrically interchangeable.
The module provides 32 output points, with a maximum load current of 0.1 A per point and 2 A per common connection. Its transistor switching architecture is suitable for repetitive DC switching operations where mechanical relay contacts are unnecessary.
In a packaging machine, for example, the TR4B can operate compatible pneumatic valve circuits and machine-status indicators. The PLC activates individual channels according to sensor feedback and programmed operating sequences, allowing multiple field devices to be coordinated through one output module.
The 2MLQ-TR4B is particularly relevant to installations using PNP-compatible field wiring. Correct selection requires checking the load voltage, output polarity, individual channel current, and common-group current before connecting field equipment.
| Parameter | Specification |
|---|---|
| Manufacturer | Honeywell |
| Model | 2MLQ-TR4B |
| Product Type | 32-Point Transistor Output Module |
| Product Series | MasterLogic-200 |
| Output Type | Transistor Output (Source Type / PNP) |
| Output Points | 32 |
| 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, 2 A / COM |
| Off-State Leakage Current | 0.1 mA or less |
| Maximum Inrush Current | 4 A / 10 ms or less |
| Maximum ON-State Voltage Drop | DC 0.3 V or less |
| Surge Absorber | Zener Diode |
| OFF-to-ON Response Time | 1 ms or less |
| ON-to-OFF Response Time | 1 ms or less (rated resistive load) |
| Common Configuration | 32 Points / 1 COM |
| Current Consumption | 130 mA (all points ON) |
| External Power Supply | DC 12/24 V ±10% |
| Maximum Ripple Voltage | 4 Vp-p |
| External Power Supply Current | 10 mA or less (DC 24 V connection) |
| Operation Indicator | Output ON LED |
| External Connection | 40-Pin Connector |
| Recommended Cable Size | 0.3 mm² |
| Dimensions | 114 × 48 × 127 mm |
| Weight | 0.1 kg |
1. 32-Point Digital Output
The module provides 32 transistor output channels for controlling external DC equipment. This channel count is suitable for machinery requiring multiple independently controlled devices without occupying additional PLC output module positions.
2. Sourcing PNP Output Configuration
The 2MLQ-TR4B uses sourcing transistor outputs. When a channel switches ON, the output supplies positive voltage to the connected load. The external circuit must be arranged with the appropriate return connection for PNP switching.
3. DC 12/24 V Load Support
The module supports DC 12 V and DC 24 V rated loads, with an allowable operating range of DC 10.2–26.4 V. This makes it suitable for common industrial DC control circuits.
4. Photo Coupler Isolation
Photo coupler isolation separates the output control circuitry from the internal PLC signal circuitry. This helps limit the direct transfer of electrical disturbances between the controller and external load circuits.
5. Fast Transistor Switching
The specified OFF-to-ON and ON-to-OFF response times are 1 ms or less under the applicable conditions. This is useful for repetitive switching sequences and automated equipment requiring rapid output changes.
6. Defined Current Capacity
Each output point supports a maximum load current of 0.1 A, while the common connection supports up to 2 A. Both limits must be considered when distributing connected loads.
7. Integrated Zener Diode Surge Absorber
The output circuit incorporates a Zener diode surge absorber to help suppress voltage transients associated with switching operations. Additional protection should be evaluated according to the connected load characteristics.
8. 40-Pin External Connection
A 40-pin connector provides the external wiring interface for the module’s 32 output channels. This arrangement supports organized field wiring in modular PLC installations.
9. LED Output Indication
The output status indicators allow technicians to identify active channels during commissioning and maintenance. They are useful when checking whether the module is responding to PLC output commands.
The 2MLQ-TR4B receives digital output commands from the MasterLogic-200 CPU and converts them into transistor switching signals for external DC loads.
Its sourcing output arrangement uses PNP transistor switching. In a typical circuit, the load is connected between the module’s output and the negative DC return. When the PLC activates a channel, the corresponding transistor conducts and supplies positive voltage to the load.
When the output command is removed, the transistor switches OFF and interrupts the current supplied to the connected device.
The module’s photo coupler isolation separates the internal control signal from the external output circuit. This allows the PLC to operate field devices through the transistor output interface while maintaining the specified electrical isolation.
Typical Output Switching Sequence:
Example: Solenoid Valve Operation
In an automated material handling system, the PLC controls several pneumatic solenoid valves through the 2MLQ-TR4B. When a position sensor confirms that a component has reached the required location, the PLC activates the corresponding output channel.
The transistor supplies positive DC voltage to the compatible valve coil, causing the pneumatic valve to change state. Once the programmed movement is complete, the CPU removes the output command and the channel switches OFF.
This arrangement allows multiple pneumatic functions to be coordinated through the module’s 32 output channels.
Within the MasterLogic-200 architecture, the 2MLQ-TR4B functions as the physical output interface between the PLC CPU and external DC field devices.
The CPU executes the application program and determines when individual outputs should operate. The TR4B performs the corresponding transistor switching operations using its sourcing output circuits.
Its PNP configuration is particularly relevant when the field devices and wiring arrangement are designed for positive-side switching. This makes it important to distinguish the TR4B from the TR4A, even though both modules provide 32 output points and have similar current ratings.
The module can be incorporated into compatible MasterLogic-200 I/O configurations alongside digital input modules, analog modules, CPU units, and system power supplies.
| Control System Component | Function |
|---|---|
| 2MLQ-TR4B | 32-point sourcing transistor output |
| 2MLQ-TR4A | 32-point sinking transistor output |
| 2MLQ-TR2B | 16-point sourcing transistor output |
| 2MLQ-TR8B | 64-point sourcing transistor output |
| 2MLQ-TR2A | 16-point sinking transistor output |
| 2MLQ-TR8A | 64-point sinking transistor output |
| 2MLQ-RY1A | 8-point relay output |
| 2MLQ-RY2A | 16-point relay output |
| 2MLQ-RY2B | 16-point relay output with varistor |
| 2MLI-D24B | 32-point digital input module |
| 2MLI-D28B | 64-point digital input module |
| 2MLI-CPUH | High Performance IEC CPU |
| 2MLI-CPUS | Standard IEC CPU |
| 2MLP-ACF1 | AC Power Supply Module |
| 2MLP-DC42 | DC Power Supply Module |
| 2MLB-M06A | Main CPU Base |
| 2MLB-E08A | Expansion I/O Base |
| Application | Output Control Function |
|---|---|
| Packaging Machinery | Controls compatible DC solenoid valves and indicator circuits |
| Automated Assembly Lines | Switches pneumatic actuators and auxiliary control devices |
| Conveyor Systems | Controls equipment interfaces and machine-status signals |
| Material Handling | Operates compatible PNP-controlled field devices |
| Automotive Manufacturing | Handles distributed machine output signals |
| Pneumatic Automation | Activates valve coils for clamping and positioning operations |
| Industrial Sorting Systems | Controls pneumatic diverters and sorting mechanisms |
| Machine Tool Automation | Switches auxiliary functions and programmed interlocks |
| Automated Inspection Equipment | Activates external devices according to inspection results |
| Component | Product Type | Application |
|---|---|---|
| 2MLQ-TR4A | 32-Point Transistor Output Module (Sink) | Alternative NPN output configuration |
| 2MLQ-TR2B | 16-Point Transistor Output Module (Source) | Lower-density PNP output applications |
| 2MLQ-TR8B | 64-Point Transistor Output Module (Source) | Higher-density PNP output applications |
| 2MLQ-TR2A | 16-Point Transistor Output Module (Sink) | 16-point NPN output control |
| 2MLQ-TR8A | 64-Point Transistor Output Module (Sink) | Higher-density NPN output control |
| 2MLQ-RY2A | 16-Point Relay Output Module | Switching applications requiring relay contacts |
| 2MLQ-RY2B | 16-Point Relay Output Module with Varistor | Relay switching with integrated surge suppression |
| 2MLI-D24B | 32-Point Digital Input Module | Receives discrete field signals |
| 2MLI-D28B | 64-Point Digital Input Module | Receives higher-density digital signals |
| 2MLI-CPUH | High Performance CPU Module | Executes PLC application logic |
| 2MLI-CPUS | Standard CPU Module | Standard PLC processing |
| 2MLP-ACF1 | AC Power Supply Module | Supplies PLC operating power |
| 2MLP-DC42 | DC Power Supply Module | Supplies PLC operating power |
| 2MLB-M06A | Main CPU Base | Houses CPU and associated modules |
| 2MLB-E08A | Expansion I/O Base | Supports additional I/O modules |
| Model | Product Description |
|---|---|
| 2MLQ-TR4A | MasterLogic-200 32-Point Transistor Output Module (Sink Type) |
| 2MLQ-TR2B | MasterLogic-200 16-Point Transistor Output Module (Source Type) |
| 2MLQ-TR8B | MasterLogic-200 64-Point Transistor Output Module (Source Type) |
| 2MLQ-TR2A | MasterLogic-200 16-Point Transistor Output Module (Sink Type) |
| 2MLQ-RY2A | MasterLogic-200 16-Point Relay Output Module |
| 2MLI-D24B | MasterLogic-200 32-Point Digital Input Module |
The TR4B uses sourcing PNP transistor outputs, while the TR4A uses sinking NPN transistor outputs. The difference determines how positive voltage and the load return are connected in the external circuit. The correct model must match the field device wiring arrangement.
It can control a compatible DC 24 V relay coil if the coil current remains within the 0.1 A per-point limit and the common current limit is respected. The coil’s inrush characteristics and inductive switching requirements should also be evaluated.
A load exceeding the specified per-point current should not be connected directly to the output. An appropriately rated external interface relay or switching device can be used so that the PLC output controls the interface rather than carrying the full load current.
No. The TR4B is a sourcing-output module. It should be used with compatible PNP switching circuits. For NPN sinking applications, the corresponding 2MLQ-TR4A is the relevant alternative.