Industrial Edge ControllerA pressure sensor cannot decide to shut off a pump.RetroRelay can.
A remote well pad has sensors, pumps, and valves, and nothing intelligent connecting them. The devices speak Modbus but cannot act on what they read. A full industrial PLC costs thousands and needs a specialist to program. RetroRelay is a drop-in edge controller: it sits on the network, reads the field devices, runs the control logic, and serves a modern dashboard, all from a single chip.
The status quo
Why small sites stay dumb
Well pads, pump stations, and compressor skids run on equipment that can measure but cannot reason. Closing that gap has always meant a PLC and a programmer.
01Dumb devicesSensors and drives speak Modbus but carry no logic. They cannot say: if differential pressure drops below ten, close the well.
02A PLC is overkillAn Allen-Bradley or Siemens PLC for simple site logic costs thousands of dollars and needs a specialist programmer to commission and change.
03Blind operationsWithout local intelligence, an operator sees nothing until they drive hours to a remote site and plug in a laptop.
04Every vendor speaks differentlyOne device is big-endian, the next swaps its bytes. Integers, floats, and register offsets all need normalizing before two vendors' equipment can interoperate.
How it works
A drop-in brain for the edge
RetroRelay reads the field devices, runs deterministic control logic on-device, and presents it all through a browser. No cloud, no PLC programmer, no firmware change per site.
Dual-role ModbusRetroRelay polls local field sensors as a Modbus master while simultaneously serving that same data to a central SCADA system as a slave. One box, both sides of the conversation.
Visual logic, no codeA Node-RED-style logic builder in the browser. Calculated tags, comparison rules, hysteresis deadbands, and on-delay and off-delay timers, wired by drag and drop, executing deterministically on the chip.
Commissioning in minutesA first-time wizard walks from WiFi to use case to live data. Pick a profile, chemical injection, gas compression, or plunger lift, and the tag map, register template, and starter logic are applied for you.
A modern dashboard on a chipThe entire React dashboard is compressed and served straight from the controller's flash memory, streaming live tag updates over websockets. Use-case schematics, gauges, and trends, with no internet required.
Under the hood
DevOps practices, on operational hardware
In plain termsRetroRelay brings the discipline of modern software, version tracking, over-the-air updates, automated testing, and configuration as data, to a class of industrial hardware that has historically had none of it.
The engineeringAn ESP32-S3 dual-core running a real-time OS with a deterministic scheduler. The Modbus engine handles RTU and TCP concurrently and normalizes byte order across vendors, so equipment from different makers interoperates. A central tag store sits at the heart of it, and an on-device logic engine reads from it with math, comparison, and timer blocks. Configuration, the tags, register maps, and logic, is data rather than compiled-in code, stored as JSON on the device. The frontend is a React app with a drag-and-drop visual logic builder, compressed and served straight from the controller's flash over websockets.
ESP32-S3FreeRTOSC++Modbus RTU / TCPMQTTReactTypeScript
Where it is
In commissioning
The protocol engine, the logic engine, the commissioning wizard, the three use-case dashboards, and the visual logic builder all run on hardware. RetroRelay is in the commissioning and beta stage; the next horizons are a broader device-template library and protocols beyond Modbus.
v1.0
production-ready firmware, in commissioning
3 profiles
chemical injection, gas compression, plunger lift, out of the box
Dual-role
Modbus master and slave running at the same time
On-chip
the full React dashboard served from the controller's flash
ShippedProtocol and logic engineDual-role Modbus over RTU and TCP, byte-order normalization across vendors, the central tag store, and the on-device logic engine with math, comparison, and timer blocks.
ShippedCommissioning and dashboardsThe first-time setup wizard, the three use-case profile bundles, the HMI dashboards, and the browser-based visual logic builder wired to the firmware.
ActiveDevice template libraryAn importable per-device template format so any field device, not only the three built-in profiles, can be mapped without a firmware change.
PlannedMulti-protocol and fleetA protocol abstraction layer for DNP3 and OPC-UA, protocol translation between them, and fleet-wide management with over-the-air updates.
Every piece of industrial hardware in the field should have a box like this between it and the rest of the world: intelligent, visible, and updatable, without a SCADA overhaul.
