Product Overview
The Ebyte NA611-S is a high-performance, highly reliable WiFi serial server that bridges RS485 serial devices to WiFi networks. Operating in the 2.4GHz band (IEEE 802.11 b/g/n), it enables legacy RS485 instruments, PLCs, meters, and sensors to connect to cloud platforms and SCADA systems without hardware redesign.
- Model: NA611-S
- Serial Interface: RS485
- WiFi Standard: IEEE 802.11 b/g/n (2.4GHz)
- Working Frequency: 2.412–2.472GHz
- Network Protocols: TCP / UDP / HTTP / MQTT
- Modbus: Automatic Modbus RTU ⇔ TCP conversion
- WiFi Modes: AP / STA / WiFi Direct
- Socket Connections: 4-way simultaneous
- Cloud Support: Alibaba Cloud, Baidu Cloud, OneNet, standard MQTT brokers
- Power Supply: DC 8–28V (wide voltage)
- Mounting: DIN-rail (guideway design)
- Weight: 134g ± 5g
- Firmware: FOTA (Firmware Over-The-Air) remote upgrade
- Operating Temp: -40℃ to +85℃ (industrial grade)
- Applications: Industrial automation, smart metering, PLC networking, SCADA, building management, energy monitoring
Technical Specifications
| Parameter | Value / Description |
|---|---|
| Model | NA611-S |
| Serial Interface | RS485 |
| WiFi Standard | IEEE 802.11 b/g/n |
| Working Frequency | 2.412–2.472GHz (2.4GHz band) |
| Network Protocols | TCP / UDP / HTTP / MQTT |
| Socket Connections | 4-way simultaneous |
| WiFi Operating Modes | AP (Access Point) / STA (Station) / WiFi Direct |
| Modbus Support | Automatic Modbus RTU ⇔ TCP conversion; Storage Gateway; Auto-Polling Gateway; Common Gateway |
| Cloud Platforms | Alibaba Cloud, Baidu Cloud, OneNet, standard MQTT brokers |
| HTTP Support | HTTP Client / WebSocket |
| Heartbeat | Network heartbeat packets & serial port heartbeat packets |
| Firmware Upgrade | FOTA (Firmware Over-The-Air) remote upgrade |
| Power Supply | DC 8–28V (wide voltage input) |
| Weight | 134g ± 5g |
| Mounting | DIN-rail (guideway / snap-on) |
| Indicator LEDs | Intuitive multi-color status indicators (power, WiFi, data) |
| Operating Temp | -40℃ to +85℃ (industrial grade) |
| Certifications | CE, RoHS |
| Updated | March 2026 |
Product Details
Basic Functions — RS485 ⇄ WiFi Transparent Bridge
The NA611-S performs bidirectional transparent data conversion between RS485 serial and WiFi network. Any data received on the RS485 port is forwarded to the configured WiFi socket destination, and vice versa — no protocol programming required on the host device. Supports up to 4 simultaneous socket connections (TCP Client/Server, UDP).
Point-to-Point Antenna Matching Recommendation
For optimal WiFi link quality in industrial environments, Ebyte provides antenna matching recommendations for point-to-point deployments. Proper antenna selection and placement ensures reliable 2.4GHz coverage across factory floors, warehouses, and outdoor installations.
Fully Functional Gateway Configuration
In gateway mode, the NA611-S acts as a protocol converter between RS485 Modbus RTU devices and TCP/IP networks. Supports multiple gateway sub-modes:
| Gateway Mode | Description |
|---|---|
| Storage Gateway | Buffers RS485 data locally and uploads to cloud/server on schedule or trigger |
| Auto-Polling Gateway | Automatically polls RS485 slave devices at configurable intervals; forwards responses to network |
| Common Gateway | Standard transparent RS485⇔WiFi bridge; passes data as-is between serial and network |
Storage Gateway
The Storage Gateway mode enables the NA611-S to buffer RS485 serial data locally when network connectivity is unavailable, then automatically upload buffered data once the connection is restored. Prevents data loss in intermittent network environments.
Automatically Polling Gateway
Configurable auto-polling engine queries RS485 Modbus RTU slave devices at user-defined intervals without requiring a host controller. Ideal for meter reading, sensor polling, and SCADA data acquisition where a central master is not available at the field level.
Common Gateway Mode
Standard transparent gateway: RS485 data is forwarded to the configured TCP/UDP server or MQTT broker without modification. Supports simultaneous connections to multiple cloud endpoints.
Automatic Modbus RTU ⇔ TCP Conversion
Built-in Modbus protocol converter automatically translates between Modbus RTU (RS485 serial) and Modbus TCP (Ethernet/WiFi) without any external software or middleware. Enables direct integration of RS485 Modbus devices with SCADA systems, HMIs, and cloud platforms that use Modbus TCP.
WiFi Modes: AP / STA / WiFi Direct
Three flexible WiFi operating modes:
| Mode | Description | Typical Use Case |
|---|---|---|
| STA (Station) | Connects to an existing WiFi router/AP as a client | Factory WiFi network, office LAN |
| AP (Access Point) | Creates its own WiFi hotspot; devices connect directly to NA611-S | Standalone deployment, no router available |
| WiFi Direct | Peer-to-peer WiFi connection without a router | Direct laptop/tablet configuration and monitoring |
HTTP Client / WebSocket Support
Beyond TCP/UDP, the NA611-S supports HTTP Client and WebSocket protocols, enabling direct integration with REST APIs, web dashboards, and real-time browser-based monitoring applications without a middleware server.
Network & Serial Heartbeat Packets
Dual heartbeat mechanism maintains connection reliability:
- Network Heartbeat: Periodically sends keep-alive packets to the server to detect and recover from dropped TCP connections
- Serial Heartbeat: Sends configurable data frames to the RS485 device at intervals to verify serial link health
FOTA — Firmware Over-The-Air Remote Upgrade
Supports remote firmware updates via WiFi without physical access to the device. Enables fleet-wide firmware management for deployed units in the field — critical for long-term maintenance of industrial IoT installations.
Intuitive LED Status Indicators
Multi-color LED indicators provide at-a-glance status for power, WiFi connection, and serial data activity — simplifying field installation, commissioning, and troubleshooting without a laptop or configuration tool.
DIN-Rail Mounting — Industrial Cabinet Ready
Standard DIN-rail (guideway) snap-on mounting fits directly into industrial control panels and distribution boards. The 8–28V DC wide-voltage input accepts 12V and 24V industrial power rails without additional regulation.
Serial Port Server Series — Triple-Proof Coating
Related Products
| Model | Key Feature |
|---|---|
| NA111 | RS232/RS485 to WiFi serial server (compact) |
| NB114 | RS485 to Ethernet serial server (RJ45) |
| NE2-D11 | Dual-port Ethernet serial server |
| NE2-D14 | 4-port Ethernet serial server |
| NA611 Series | NA611-S (RS485) / NA611-D (RS232+RS485) variants |
| NB1A1 | 5G edge computing serial-to-Ethernet gateway |
| NB183 | RS485 to 4G/LTE serial server |
| NB124 | Multi-port 4G serial server |
Ideal Applications
Resources
Download Datasheet & User Manual (PDF)Download CE / RoHS Certificates
Bulk Purchase & OEM Inquiry
FAQ
Q: What is the difference between the NA611-S and NA611-D?
A: The NA611-S has a single RS485 interface. The NA611-D adds both RS232 and RS485 ports, enabling simultaneous connection of two different serial devices to the same WiFi network.
Q: Does the NA611-S support Modbus TCP to RTU conversion automatically?
A: Yes. The built-in Modbus protocol converter automatically translates Modbus TCP commands from the network side into Modbus RTU frames on the RS485 side, and vice versa. No external software or middleware is required.
Q: Can the NA611-S connect to MQTT brokers like AWS IoT, Azure IoT Hub, or HiveMQ?
A: Yes. The NA611-S supports standard MQTT protocol and is compatible with any standard MQTT broker, including AWS IoT Core, Azure IoT Hub, HiveMQ, Mosquitto, Alibaba Cloud IoT, Baidu Cloud, and OneNet.
Q: How do I configure the NA611-S?
A: Configuration is done via a web browser. In AP mode, connect your PC or phone to the NA611-S WiFi hotspot and open the web UI (default IP: 192.168.4.1). All parameters — WiFi SSID/password, server IP, port, protocol, Modbus settings — are configured through the browser interface. No special software required.
Q: What power supply does the NA611-S require?
A: DC 8–28V wide-voltage input. Compatible with 12V and 24V industrial power supplies. No additional voltage regulation needed for standard industrial cabinet power rails.
Q: Does the NA611-S support FOTA (remote firmware update)?
A: Yes. Firmware can be updated remotely over WiFi (FOTA) without physical access to the device. This enables centralized firmware management for large deployments of NA611-S units in the field.
Q: How many simultaneous connections does the NA611-S support?
A: Up to 4 simultaneous socket connections (TCP Client, TCP Server, UDP). This allows the NA611-S to report data to multiple servers or cloud platforms simultaneously.
Q: What is the Auto-Polling Gateway mode used for?
A: Auto-Polling Gateway mode allows the NA611-S to autonomously query RS485 Modbus RTU slave devices at configurable intervals — without requiring a host PLC or SCADA master at the field level. The polled data is forwarded to the configured network destination (TCP server, MQTT broker, etc.).
