Converter RS485/Ethernet ETS01

Compact galvanically isolated Ethernet to RS485 converter. The converter offers configuration via a web interface and supports multiple protocols: Modbus TCP, Modbus RTU over TCP, Modbus RTU, MQTT, and HTTP. It is designed for DIN-rail mounting and with an universal power supply from 85 to 265 VAC/DC.

The ETS01 is a universal galvanically isolated Ethernet/RS485 converter that enables the conversion of Modbus TCP, Modbus RTU over TCP, and MQTT protocols to the RS485 interface - Modbus RTU. This converter supports up to 10 clients on the Modbus TCP interface and up to 10 clients on the Modbus RTU over TCP interface simultaneously. Messages from each interface are processed sequentially in the order they are received and then forwarded to the RS485 interface.

Additionally, the converter allows for the extension of the RS485 line via an Ethernet network, making it an ideal solution for devices equipped only with an RS485 interface that are located far apart, provided an Ethernet network is available nearby. Furthermore, the converter supports communication using the MQTT protocol, enabling access to the converter from anywhere without the need to create a VPN network.

The converter is configured through a user-friendly web interface.

Modbus TCP is a modified version of the Modbus protocol, adapted for network transmission over Ethernet. The Modbus RTU protocol is used on the RS485 serial bus. The converter requires its own logic to transform a Modbus TCP frame into a Modbus RTU frame format and then send this frame to the RS485 - Modbus RTU interface. Similarly, the converter must convert a frame received from the RS485 interface back into Modbus TCP format and send it back to the client.

This ensures bidirectional communication between devices using different versions of the Modbus protocol. For proper functionality, the converter must analyze the received data and modify it accordingly.

The Modbus RTU over TCP protocol is a standard Modbus RTU frame, typically used on the RS485 bus, augmented with a TCP/IP header. This allows the standard Modbus RTU frame to be transmitted over a network based on the TCP/IP protocol while preserving the original structure and functionality of the Modbus RTU frame.

The converter does not analyze the content of the frames received on the Modbus RTU over TCP interface. Upon reception, it removes the TCP/IP header from the incoming frame and forwards it to the RS485 interface. Conversely, frames received from the RS485 interface are supplemented with a TCP/IP header and sent back to the client.

The RS485 Ethernet Expander is an interface designed to extend the RS485 bus over an Ethernet network. This is an ideal solution for devices equipped only with an RS485 interface that are located far apart but have an Ethernet network available nearby. To utilize the RS485 Ethernet Expander functionality, two ETS01 converters are required.

Setting up this interface is very simple – both converters must be configured to use the same TCP/IP port to enable mutual communication, and each converter must be assigned the IP address of the other.