M91-2-UA2 Unitronics M91 Textual display and keyboard HMI and PLC onboard I/Os expands up to 150 I/Os

Why Choose the Unitronics M91-2-UA2 Micro PLC with Integrated Text HMI?

The Unitronics M91-2-UA2 is a compact micro PLC with an integrated text-based HMI from the Unitronics M90/M91 series. Designed for small to medium industrial automation systems, the controller combines programmable logic control, operator interface and onboard I/O in a single device, helping reduce panel space, wiring complexity and installation cost.

The controller features a built-in two-line LCD display capable of showing 16 characters per line and a 15-key keypad, enabling operators to view machine status, navigate menus and modify parameters directly from the device. This integrated design eliminates the need for a separate HMI while maintaining clear operator interaction.

The M91-2-UA2 offers a flexible I/O configuration with 10 digital inputs, 2 configurable analogue / temperature inputs, 10 transistor outputs and 2 analogue outputs. These capabilities make it suitable for controlling sensors, actuators and analogue process signals in industrial automation environments.

Key Features

• Integrated PLC and text HMI in a single compact controller.
• 2-line LCD display with 16 characters per line.
• 10 digital inputs for automation signals and sensors.
• 2 configurable analogue / temperature inputs supporting voltage, current or thermocouple signals.
• 10 transistor outputs for controlling actuators.
• 2 analogue outputs for process control signals.
• High-speed counter capability for encoder or frequency measurement.
• RS232 and RS485 serial communication.
• I/O expansion capability for additional modules.

Technical Specifications

• Manufacturer: Unitronics
• Series: M90 / M91
• Model: M91-2-UA2
• Controller type: Micro PLC with integrated text HMI
• Display: STN LCD text display
• Display size: 2 lines × 16 characters
• Keypad: 15 operator keys
• Supply voltage: 24 V DC
• Digital inputs: 10 inputs
• Configurable inputs: 2 analogue / thermocouple / digital inputs
• Digital outputs: 10 transistor outputs
• Analogue outputs: 2 outputs (0–10 V or 4–20 mA)
• High-speed inputs: counter / encoder capable inputs
• Communication ports: RS232 / RS485
• Program capacity: approx. 36 kB ladder logic
• Expansion capability: supports I/O expansion modules
• Mounting: DIN rail or panel mount
• Protection rating: IP65 / NEMA 4X when panel mounted
• Operating temperature: 0 °C to 50 °C

Typical Applications

• Machine automation and OEM equipment.
• Water treatment and pump control systems.
• Industrial process monitoring and analogue control.
• Packaging and material handling equipment.
• Standalone automation systems requiring a simple operator interface.

Trusted by Automation Engineers

Unitronics M90 and M91 controllers are widely used because they combine PLC logic control and a built-in operator interface in a compact, cost-effective platform for industrial automation.