Product Overview

The Honeywell 2MLQ-TR1C is an 8-point isolated transistor output module belonging to the MasterLogic-200 PLC system. It uses a sinking output configuration and supports a maximum load current of 2 A per output point. Its electrical configuration distinguishes it from the standard high-density transistor output modules in the same series.

In practical machine control, not every application requires 32 or 64 output channels. Some equipment uses a smaller number of DC actuators or switching devices, but each circuit requires a higher current capacity. The TR1C addresses this type of application with eight individually controlled output points.

The module supports DC 12/24 V load circuits and uses relay isolation. Each output point has an individual COM connection, allowing the field wiring to be organized separately. This is particularly useful in machinery where different actuator circuits operate independently and require clear wiring identification during commissioning and maintenance.

Typical applications include pneumatic control panels, automated assembly equipment, packaging machinery, and industrial machines with multiple DC switching devices. The PLC CPU handles the sequence and interlock logic, while the TR1C executes the corresponding output commands.

When selecting this module, engineers should pay particular attention to its sinking output arrangement, individual channel current rating, and external load requirements. These characteristics are more important than simply comparing the number of output points with other MasterLogic-200 modules.

Technical Specifications

Product Features

1. Eight Isolated Transistor Output Points

The TR1C provides eight independently controlled transistor output channels. Its isolated output arrangement is suitable for control panels where individual field circuits need separate switching connections.

2. 2 A Maximum Load Current per Point

Each output point supports a maximum load current of 2 A. This higher individual channel rating distinguishes the TR1C from the standard high-density transistor output modules in the MasterLogic-200 family.

3. Sinking Output Configuration

The module uses sinking transistor outputs. External DC loads must be connected with the correct supply polarity and current-return arrangement.

4. DC 12/24 V Load Compatibility

The rated load voltage is DC 12/24 V, with an operating range of DC 10.2–26.4 V. This supports common industrial DC control circuits.

5. Individual COM Connections

Each output point has its own COM connection. This arrangement allows the eight field circuits to be wired individually rather than sharing a single common connection.

6. Relay Isolation

Relay isolation is specified for the output module. This characteristic should be considered when planning the electrical interface between the PLC system and external equipment.

7. Zener Diode Surge Absorption

The output circuit includes a Zener diode surge absorber. The characteristics of connected inductive loads should still be evaluated when selecting external circuit protection.

8. Defined Switching Response

The OFF-to-ON response time is 3 ms or less, while the ON-to-OFF response time is 10 ms or less under rated resistive-load conditions.

9. LED Output Status Indication

The Output ON LED provides a visual indication of channel activity. Technicians can use this indication when checking output operation during commissioning and fault diagnosis.

10. 18-Point Terminal Block Connection

The module uses an 18-point terminal block connector for external wiring, providing the connection interface for its eight output circuits.

Working Principle

The 2MLQ-TR1C operates as the output switching stage of a MasterLogic-200 PLC system. It receives output commands from the CPU and switches the connected DC field circuits according to the PLC program.

When the CPU activates an output point, the corresponding transistor switching circuit changes to its conducting state. With the sinking configuration, the output provides a current path toward the DC negative return. The connected load operates when the external supply and wiring conditions are correct.

When the CPU removes the output command, the transistor circuit returns to its inactive state and interrupts the normal load current.

The individual COM arrangement allows each output point to have a separate common connection. This is useful when several field devices operate independently and their wiring needs to be clearly separated.

For example, consider an automated assembly machine with eight DC actuator circuits. The PLC receives position signals from sensors and determines when each actuator should operate. The TR1C switches the corresponding output channel, allowing the machine to execute its programmed sequence.

The module’s response characteristics also need to be considered when calculating switching intervals. The specified OFF-to-ON response is 3 ms or less, while the ON-to-OFF response is 10 ms or less under rated resistive-load conditions.

Typical Control Sequence:

1. Field sensors transmit equipment status signals to the MasterLogic-200 CPU.
2. The CPU evaluates the operating conditions and programmed interlocks.
3. The CPU sends an output command to the assigned TR1C channel.
4. The transistor output circuit switches to its active state.
5. Current flows through the connected DC load.
6. The actuator or switching device performs its assigned operation.
7. When the programmed condition is satisfied, the CPU removes the output command.

Role in MasterLogic-200 Control Architecture

Within the MasterLogic-200 architecture, the 2MLQ-TR1C provides the digital output interface between PLC logic and external DC equipment.

The CPU executes the control program, processes input information, and determines the required output states. The TR1C handles the corresponding electrical switching operations. This division allows machine sequence logic to remain in the controller while individual field devices are operated through dedicated output channels.

The TR1C is particularly relevant when the application requires eight isolated sinking outputs with a maximum current rating of 2 A per point. It should not be treated as an equivalent replacement for the higher-density TR2A, TR4A, or TR8A modules, which have different channel counts and current ratings.

Industrial Applications

Installation and Maintenance

1. Verify Module Identification: Confirm that the installed module is 2MLQ-TR1C and distinguish it from other MasterLogic-200 transistor output variants.
2. Check Output Configuration: Verify that the external control circuit is compatible with the sinking output arrangement.
3. Confirm Load Voltage: Ensure that the connected equipment operates within the specified DC 10.2–26.4 V load voltage range.
4. Observe Current Ratings: Keep each output channel within its maximum specified load current of 2 A.
5. Inspect COM Connections: Check the individual common connection for each output point and confirm that the field wiring matches the circuit diagram.
6. Check Terminal Connections: Inspect the 18-point terminal block connector for loose wires, damaged contacts, or incorrect terminal assignments.
7. Verify Supply Polarity: Confirm positive and negative DC supply connections before energizing the external circuits.
8. Evaluate Load Characteristics: Check the current requirements and switching characteristics of connected solenoid valves, actuators, and other DC devices.
9. Review Switching Frequency: Consider the specified maximum switching frequency of 3,600 times per hour when evaluating repetitive switching applications.
10. Monitor LED Indicators: Observe the Output ON LEDs during commissioning to compare actual channel activity with PLC commands.
11. Investigate Output Faults: If a field device does not respond, inspect the PLC logic, external power supply, terminal wiring, and connected load.
12. Maintain Wiring Records: Keep updated documentation identifying output addresses, COM connections, field devices, and associated control functions.

Compatible System Components

Recommended Related Models

Key Advantages

• Eight isolated transistor output points.
• Sinking output configuration for DC control circuits.
• Maximum load current of 2 A per output point.
• Supports DC 12/24 V rated load circuits.
• Individual common connection for each output point.
• Relay isolation arrangement.
• Integrated Zener diode surge absorber.
• OFF-to-ON response time of 3 ms or less.
• ON-to-OFF response time of 10 ms or less under rated resistive-load conditions.
• Maximum switching frequency of 3,600 times per hour.
• LED output status indication.
• 18-point terminal block connection.
• Integration with the MasterLogic-200 PLC architecture.

Technical FAQs

1. What makes the 2MLQ-TR1C different from the 2MLQ-TR2A?

The main difference is the output configuration and channel rating. The TR1C provides eight isolated sinking transistor outputs with a maximum current of 2 A per point. The TR2A provides 16 sinking transistor outputs rated at 0.5 A per point. The appropriate choice depends on the required channel count and individual load current.

2. Can the 2MLQ-TR1C control DC solenoid valves?

It can be used with compatible DC solenoid valve circuits when the load voltage, current, output polarity, and external wiring meet the module’s specifications. The actual coil current and switching requirements should be checked before connecting the valve.

3. Why does each output point have an individual COM connection?

The one-point-per-COM configuration allows each output circuit to have its own common connection. This simplifies the organization of independently controlled field circuits and is particularly useful in installations where different loads require separate wiring arrangements.

4. What response time should be considered when programming machine sequences?

The specified OFF-to-ON response time is 3 ms or less. The ON-to-OFF response time is 10 ms or less under rated resistive-load conditions. These values should be considered alongside PLC scan time and the actual response characteristics of connected field devices.