Industries

Smart Gateway Modbus TCP and RTU

Problem Statement

Industrial automation integrators routinely work with a mix of old and new legacy field devices running Modbus RTU alongside modern supervisory systems and cloud platforms using Modbus TCP. Connecting the two reliably required a gateway that could handle both protocols, control field devices directly through digital I/O, connect over both wired and wireless networks, and be updated remotely without a site visit. Most available gateways covered some of these requirements but not all of them together in a single deployable unit.

Our Solution

We developed an industrial IoT gateway that handles both Modbus TCP and Modbus RTU in a single DIN rail-mounted device. It polls legacy RS485 field devices as a Modbus RTU master, while simultaneously operating as a Modbus TCP master and slave for SCADA and supervisory system integration. Six optoisolated digital inputs and four relay digital outputs allow direct control and monitoring of field devices without additional hardware. The gateway connects via WiFi and Ethernet, publishes data to cloud IoT platforms over MQTT with TLS, and buffers data locally when connectivity is interrupted. A configurable register mapping tool lets integrators add new Modbus RTU device types without any firmware changes, and FOTA with rollback protection keeps all field-deployed units updatable remotely.

Insights & Outcomes

Bridging Modbus RTU and TCP in one device removed the need for separate protocol converters, cutting hardware complexity at industrial sites. Configurable register mapping let integrators add new device types without firmware changes no engineering rework for each new deployment. Built-in 6DI/4DO handled field device control directly, local flash buffering prevented data loss during connectivity gaps, and FOTA with rollback protection made remote firmware updates safe across all deployed units eliminating site visits for maintenance entirely.