--- title: Synergy Logic SLM-RP4 – A Raspberry Pi 4 PLC with... description: Synergy Logic's SLM-RP4 is an industrial PLC built on a Raspberry Pi 4 Model B with 2GB RAM. It uses a DIN-rail mountable, fanless aluminum enclosure, 24V DC... canonical: https://daily.dev/posts/synergy-logic-slm-rp4-a-raspberry-pi-4-plc-with-modular-industrial-i-o-zkgz3fe4z twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Synergy Logic SLM-RP4 – A Raspberry Pi 4 PLC with modular industrial I/O | daily.dev og:description: Synergy Logic's SLM-RP4 is an industrial PLC built on a Raspberry Pi 4 Model B with 2GB RAM. It uses a DIN-rail mountable, fanless aluminum enclosure, 24V DC... og:url: https://daily.dev/posts/synergy-logic-slm-rp4-a-raspberry-pi-4-plc-with-modular-industrial-i-o-zkgz3fe4z og:image: https://api.daily.dev/og/posts/ZkgZ3fe4Z.png og:image:alt: Synergy Logic SLM-RP4 – A Raspberry Pi 4 PLC with modular industrial I/O og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Synergy Logic SLM-RP4 – A Raspberry Pi 4 PLC with modular industrial I/O **[CNX Software](https://daily.dev/sources/cnx-software)** · 5 min read · 0 upvotes · 0 comments ## Summary Synergy Logic's SLM-RP4 is an industrial PLC built on a Raspberry Pi 4 Model B with 2GB RAM. It uses a DIN-rail mountable, fanless aluminum enclosure, 24V DC input, and an SPI-based backplane that connects up to eight stackable I/O modules for up to 128 I/O points. It ships with Raspberry Pi OS and OpenPLC Runtime preinstalled, supporting IEC 61131-3 languages plus Python and C++ function blocks. The backplane allows I/O scan intervals from 1ms to 1000ms, defaulting to 10ms. It costs $249, with I/O modules sold separately, compared to $149 for the earlier external-I/O SL-RP4. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What is the Synergy Logic SLM-RP4 and what specs does it have? It is an industrial PLC built around a Raspberry Pi 4 Model B with 2GB RAM, DIN-rail mountable with a fanless aluminum enclosure. It takes 24V DC input, uses an SPI-based backplane supporting up to eight stackable I/O modules for up to 128 I/O points, and includes Gigabit Ethernet, WiFi 5, Bluetooth 5.0, and two micro-HDMI ports. It costs $249. _Engineers comparing Pi-based PLC hardware can track new industrial controller releases on daily.dev._ ### Which programming languages can I use with OpenPLC on the Synergy Logic SLM-RP4? OpenPLC Editor 4.3.1 or newer lets you program the controller using the IEC 61131-3 languages Ladder Diagram, Structured Text, Function Block Diagram, and Instruction List, plus Python and C++ function blocks. The controller ships with OpenPLC Runtime preinstalled along with Synergy Logic's own Python and C++ libraries. _Those choosing a PLC programming toolchain can follow coverage of OpenPLC and similar tools on daily.dev._ ### How fast can the SPI backplane on the Synergy Logic SLM-RP4 scan I/O modules? The SPI-based backplane supports adjustable I/O scan intervals ranging from 1ms to 1000ms, with 10ms set as the default. It also detects communication errors and can stop PLC execution and reset outputs to zero if errors exceed a configured limit, and a hardware watchdog helps recover from application failures. _Developers tuning real-time I/O performance can keep up with industrial controller hardware specs on daily.dev._ ## Similar posts on daily.dev - [A Linux-based Rockchip RK3506B industrial controller with RS232, RS422, RS485, CAN bus, and relays](https://daily.dev/posts/a-linux-based-rockchip-rk3506b-industrial-controller-with-rs232-rs422-rs485-can-bus-and-relays-ccrutgrxe) · CNX Software · 0 upvotes · 0 comments - [An industrial IoT ESP32-S3 PLC with Ethernet, RS232, RS485, CAN Bus, DIN Rail support](https://daily.dev/posts/an-industrial-iot-esp32-s3-plc-with-ethernet-rs232-rs485-can-bus-din-rail-support-wxy9yv7tc) · CNX Software · 0 upvotes · 0 comments - [Hands On WIth The Raspberry Pi Compute Module Zero](https://daily.dev/posts/hands-on-with-the-raspberry-pi-compute-module-zero-m4k101g9h) · Hackaday · 0 upvotes · 0 comments - [ArmSoM Sige7s Puts the RK3588S on a Raspberry Pi-Sized Board, and There's a Compute Module Too](https://daily.dev/posts/armsom-sige7s-puts-the-rk3588s-on-a-raspberry-pi-sized-board-and-there-s-a-compute-module-too-rhaq1mbpf) · It's Foss · 1 upvotes · 0 comments - [Raspberry Pi CM0-based industrial data acquisition gateway features RS-485, RS-232, DI, and DO interfaces](https://daily.dev/posts/raspberry-pi-cm0-based-industrial-data-acquisition-gateway-features-rs-485-rs-232-di-and-do-inter-oqkgqcjcv) · CNX Software · 0 upvotes · 0 comments --- Tags: [#raspberry-pi](https://daily.dev/tags/raspberry-pi) [View this post on daily.dev](https://daily.dev/posts/synergy-logic-slm-rp4-a-raspberry-pi-4-plc-with-modular-industrial-i-o-zkgz3fe4z) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Synergy Logic SLM-RP4 – A Raspberry Pi 4 PLC with modular industrial I/O","url":"https://daily.dev/posts/synergy-logic-slm-rp4-a-raspberry-pi-4-plc-with-modular-industrial-i-o-zkgz3fe4z","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/synergy-logic-slm-rp4-a-raspberry-pi-4-plc-with-modular-industrial-i-o-zkgz3fe4z"},"datePublished":"2026-10-27T09:07:03.366Z","dateModified":"2026-10-27T09:07:33.521Z","description":"Synergy Logic's SLM-RP4 is an industrial PLC built on a Raspberry Pi 4 Model B with 2GB RAM. 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