M91-2-T38 Unitronics M91 Textual display and keyboard HMI and PLC onboard I/Os expands up to 150 I/Os

Why Choose the Unitronics M91-2-T38 Micro PLC with Integrated Text HMI?

The Unitronics M91-2-T38 is a compact micro PLC with integrated text-based HMI from the Unitronics M90/M91 series. Designed for small and medium automation systems, it combines logic control, operator interface and onboard I/O in a single device, helping reduce panel wiring, hardware costs and installation time.

The controller features a two-line LCD display capable of showing 16 characters per line along with a built-in 15-key keypad, allowing operators to monitor machine status, navigate menus and modify parameters directly from the controller. This integrated design eliminates the need for a separate HMI while still providing a simple operator interface for machines and process systems.

The M91-2-T38 offers extensive onboard I/O including 22 digital inputs and 16 transistor outputs. Two inputs can operate as high-speed counters up to around 10 kHz, and two outputs support PWM high-speed control, making the controller suitable for motion monitoring, encoder feedback and fast switching applications.

Key Features

• All-in-one PLC with integrated text HMI and keypad.
• 2-line LCD display with 16 characters per line.
• 22 digital inputs including high-speed counter capability.
• 16 transistor outputs for controlling industrial loads.
• 2 high-speed counter inputs supporting encoder or frequency measurement.
• 2 high-speed PWM outputs for control applications.
• RS232 and RS485 communication supporting Modbus networking.
• I/O expansion capability for additional modules.

Technical Specifications

• Manufacturer: Unitronics
• Series: M90 / M91
• Model: M91-2-T38
• Controller type: Micro PLC with integrated text HMI
• Display: STN monochrome LCD with LED backlight
• Display size: 2 lines × 16 characters
• Keypad: 15 operator keys
• Supply voltage: 24 V DC nominal (20.4 to 28.8 V DC)
• Digital inputs: 22 inputs (including 2 high-speed counters)
• Digital outputs: 16 transistor outputs (PNP)
• High-speed outputs: 2 PWM outputs
• Communication ports: RS232 / RS485
• Protocol support: Modbus communication
• Program capacity: approx. 36 kB ladder logic
• I/O expansion: supports additional I/O modules
• Protection rating: IP65 / NEMA 4X when panel mounted
• Operating temperature: 0 °C to 50 °C

Typical Applications

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

Trusted by Machine Builders

Unitronics M90 and M91 PLCs are widely used in industrial automation because they combine programmable control and operator interface in a compact, cost-effective controller platform.