In a series of earlier blogs on the eStorm B1 BLE module, we discussed several applications of this compact wireless module — including smart metering, Bluetooth-to-serial bridging, and live demonstrations of data acquisition over BLE. Following very positive industry response, Embien has launched the eStorm B1 Evaluation Kit (EVK): a ready-to-use hardware platform incorporating the eStorm B1 module alongside a rich set of interfaces designed for real-world industrial evaluation. This blog introduces the eStorm B1 EVK in detail, with a focus on its application as a BLE-to-RS232 modbus gateway — including modbus RTU to Modbus TCP conversion and broader Industry 4.0 connectivity use cases.
RS232 Modbus Serial Interface
RS232 is one of the most enduring wired serial communication standards in industrial electronics. Introduced in 1960, it continues to be widely deployed because of its proven reliability and simplicity. RS232 operates over distances up to 15 meters at data rates up to approximately 160 Kbit/s. It is commonly found in PLCs, data acquisition systems, environmental monitors, industrial panel meters, and legacy SCADA peripherals. While UART handles the physical and link layers, the application layer is typically governed by a protocol — and for industrial environments, the dominant choice is Modbus.
Modbus is an open serial communication protocol developed for reliable information transfer between electronic devices over serial lines. A Modbus network supports one master device and up to 247 slave devices. The master device reads from or writes to registers in the slave device. Because Modbus is an open standard with no licensing fees, it is embedded into countless industrial devices across process automation, energy management, and building control systems.
The Modbus standard defines multiple transport variants: Modbus RTU and Modbus ASCII for serial communication, and Modbus TCP for Ethernet-based communication. The need to bridge between these variants — specifically modbus RTU to Modbus TCP — is a frequent requirement in modernizing legacy industrial installations. The eStorm B1 EVK addresses this precisely, functioning as a wireless modbus gateway that enables modbus RTU to Modbus TCP translation over a BLE radio link, without any physical rewiring of existing RS232 infrastructure.
Need for Wireless Communication and the eStorm B1 as a Modbus Gateway
The pressure to wirelessly enable legacy industrial equipment has accelerated sharply with the rise of Industry 4.0 and the Industrial Internet of Things (IIoT). Industry 4.0 drives intelligence into manufacturing automation and data exchange — leveraging IoT, cloud computing, and analytics to make production environments smarter, more responsive, and more efficient. Existing RS232 and RS485 infrastructure can participate in this transformation with minimal disruption using a suitable wireless modbus gateway that bridges serial data to modern connectivity layers.
Embien, responding to this industry need, developed the eStorm B1 BLE module under its eStorm series of embedded solutions. The eStorm B1 supports wireless serial communication via its UART interface and can function as a BLE-to-UART converter bridge out of the box. Building on the eStorm B1 module, Embien then launched the eStorm B1 EVK — a fully featured evaluation kit designed to support rapid, real-world validation of eStorm B1 capabilities across multiple industrial applications, including modbus RTU to Modbus TCP gateway scenarios and broader Digital Transformation Services engagements.
The eStorm B1 EVK includes the following hardware features:
- 1× RS232 or RS485 serial interface
- 1× CAN interface
- 1× LIN interface
- One analog input and one isolated digital input for external sensor interfacing
- One digital output for external load control
- Onboard EEPROM
- Onboard accelerometer
- Battery operated with integrated battery charger
- Compact dimensions with mounting holes for panel or enclosure installation
- Screw-type PCB connectors for RS232, RS485, and CAN interfaces enabling rigid, vibration-resistant connection to external devices
eStorm B1 EVK as a Wireless Modbus Gateway
The RS232 interface on the eStorm B1 EVK makes it directly suitable for wireless modbus gateway applications. The eStorm B1 EVK supports three-wire RS232 serial communication via null modem cable, exposed through a screw-type PCB terminal connector for a secure, permanent connection. Designed for rugged industrial environments, the EVK operates from a 5 V DC supply, and its RS232 receiver accepts input voltage up to ±30 V while withstanding surges up to 15 kV (HBM) on the RS232 lines. An optional protective enclosure is available for panel-mount or field-cabinet installation.
As a modbus gateway, the eStorm B1 EVK runs a fully tested Modbus Client stack, allowing it to query Modbus slave devices connected to the RS232 line and relay their data wirelessly over BLE to an Android application or cloud-connected gateway. This effectively achieves modbus RTU to Modbus TCP bridging — the RS232 side communicates using Modbus RTU, while the BLE-connected Android application or upstream gateway operates in the TCP/IP domain. Integrating this data stream with Cloud Infrastructure Services allows the acquired Modbus data to be forwarded to cloud analytics, SCADA dashboards, or enterprise systems with minimal additional infrastructure.
Key features of the eStorm B1 EVK wireless modbus gateway solution:
- Configuration of baud rate, stop bits, and data bits
- Modbus RTU and Modbus ASCII support
- Continuous data acquisition from Modbus slaves
- Notification based on change-of-value (CoV) thresholds
- Customizable application buttons for simple Modbus slave configuration
CAN-Based Embedded Device for Factory Use
Beyond the RS232 Modbus gateway application, the eStorm B1 EVK's integrated CAN interface makes it suitable for deployment as a CAN-based embedded device for factory use. Factory automation environments frequently require wireless visibility into CAN bus traffic from PLCs, motor drives, and conveyor controllers. The eStorm B1, used as a CAN-based embedded device for factory use, can bridge CAN bus data wirelessly over BLE to an Android or Linux host — enabling mobile diagnostics, wireless configuration, and remote monitoring of CAN-connected factory equipment without requiring dedicated cabling infrastructure. This positions the eStorm B1 as a versatile, cost-effective CAN-based embedded device for factory use across process automation, machine tool monitoring, and energy management applications.
Industry 4.0 Connectivity with the eStorm B1 EVK
The eStorm B1 EVK is purpose-built to accelerate Industry 4.0 connectivity in existing industrial installations. Industry 4.0 connectivity requires seamless, secure data exchange between field-level sensors and actuators, edge gateways, and cloud analytics platforms — without disrupting proven RS232 and CAN-based hardware that may have decades of operational life remaining. The eStorm B1 EVK delivers Industry 4.0 connectivity by providing BLE wireless bridging for RS232, RS485, CAN, LIN, analog, and digital interfaces in a single compact, battery-operable module. This makes it ideal for Industry 4.0 connectivity retrofit scenarios where deploying Ethernet or Wi-Fi cabling is impractical, and where BLE range and power characteristics match the deployment environment — factory floors, utility substations, agricultural equipment, and remote plant sites.
Thus the eStorm B1 EVK, acting as a wireless modbus gateway, can interface with multiple legacy devices simultaneously — enabling wireless data acquisition from existing Modbus RTU equipment, PLC control via Modbus commands, and industrial automation applications spanning machine monitoring, energy metering, and condition-based maintenance.
About Embien
Embien Technologies is a leading provider of embedded design services for industrial automation. We have developed diverse products including data acquisition systems, industrial human-machine interfaces (HMIs), BLE-based precision instruments such as pH meters, and precision measurement devices. With the eStorm B1 and eStorm B1 EVK, we are actively enabling Industry 4.0 connectivity initiatives — helping manufacturers modernize their RS232 and CAN-based field infrastructure with secure BLE wireless modbus gateway solutions that integrate seamlessly with cloud and enterprise platforms.