STMicroelectronics X-NUCLEO-PLC01A1

Overview

X-NUCLEO-PLC01A1 from STMicroelectronics is an industrial I/O expansion board enabling PLC function subset on STM32 Nucleo platforms, featuring 8-channel high-speed protected digital inputs via CLT01-38SQ7 and 8-channel high-side solid-state relay outputs via VNI8200XP, with SPI interface, diagnostic LEDs (Fault/Thermal/Power), and 24 V input capability.

For engineers reviewing the X-NUCLEO-PLC01A1 datasheet, X-NUCLEO-PLC01A1 pinout, X-NUCLEO-PLC01A1 application, or X-NUCLEO-PLC01A1 equivalent, this board supports rapid evaluation of industrial PLC operations in conjunction with X-CUBE-PLC1 firmware, Arduino UNO R3 compatibility, and seamless integration with STM32Cube-based development workflows.

Technical Context

The board implements a modular industrial I/O architecture using two core ICs: CLT01-38SQ7 provides galvanically isolated, energy-less status indication for all eight inputs and meets IEC61000-4-2 ±8 kV contact / ±15 kV air discharge ESD immunity; VNI8200XP delivers eight independently controllable high-side switches with integrated thermal warning (/TWARN), fault reporting (/FAULT), and power-good (PG) signaling.

Communication occurs over isolated SPI: Si8661 digital isolator separates MCU-side SPI signals (SCK/MOSI/MISO/CS) from the 24 V I/O domain, while dedicated enable lines (OUT_EN, VNI_OUT_EN) and watchdog control (VNI_WD) support safe startup and fail-safe operation in harsh environments.

Key Specifications

Availability

X-NUCLEO-PLC01A1 is available at Aetrix Electronics and suitable for industrial automation prototyping, PLC training systems, and embedded control validation requiring stable component supply, RoHS-compliant design, and Arduino UNO R3 mechanical compatibility.

Supply support for X-NUCLEO-PLC01A1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing microcontrollers, analog ICs, power management devices, and sensors for industrial, automotive, and consumer applications.

X-NUCLEO-PLC01A1 belongs to ST's Nucleo ecosystem expansion board family, engineered to accelerate industrial control development by bridging STM32 MCUs with ruggedized, standards-compliant I/O interfaces for real-world factory-floor deployment.

FAQ

Does X-NUCLEO-PLC01A1 require external power beyond the STM32 Nucleo board?

Yes - it requires a separate 24 V DC supply for the I/O section, delivered via J8 (input connector) or J10 (output connector). The board does not draw 24 V power from the Nucleo board; only 5 V and 3.3 V are sourced from the Nucleo via the Morpho or Arduino connectors for logic and isolation circuitry.

Can X-NUCLEO-PLC01A1 be used with non-STM32 Nucleo boards?

No - it is mechanically and electrically designed for STM32 Nucleo boards with standard Morpho pin headers and Arduino UNO R3 layout. While SPI and GPIO signals are accessible, firmware, pin mapping, and power sequencing dependencies (e.g., OUT_EN timing, VNI_WD assertion) are validated exclusively with STM32Cube HAL and X-CUBE-PLC1.

What protection features are implemented on the input side?

The CLT01-38SQ7 provides overvoltage clamping (via integrated TVS), reverse polarity protection, and transient immunity per IEC61000-4-4 (EFT) and IEC61000-4-5 (surge). Each input channel includes energy-less LED status indication without loading the field device, enabling true "dry contact" monitoring.

Is isolation between MCU and I/O sides reinforced or basic?

It uses Si8661 digital isolators rated for 3.75 kVRMS reinforced isolation per UL 1577, supporting continuous 24 V I/O domain operation while maintaining safety separation from the 3.3 V/5 V MCU domain - critical for CE/UL compliance in industrial control equipment.