NA111 is a robust industrial-grade serial port server designed for seamless RS485 data ⇌ Ethernet data conversion. It features integrated Modbus, MQTT, and HTTP IoT gateways, making it an ideal networking solution for serial devices and PLCs in industrial automation and IoT ecosystems.
Technical Specifications
| Supply Voltage | DC 8~28V |
| Interface Type | RJ45 (Ethernet) to 3*3.81mm Phoenix Terminal (RS485) |
| Network Protocols | IP, TCP/UDP, HTTPD, IPV4 |
| IoT Gateway Modes | Modbus Gateway, MQTTC/HTTPC Support |
| Dimensions | 92 * 66 * 30 mm |
| Weight | 129g ± 5g |
Core Features
- Multiple Gateway Modes: Supports Modbus multi-host, storage-type gateways, and MQTT/HTTP IoT protocols for direct cloud connectivity.
- Industrial-Grade Design: Built to last with a wide voltage range and a shell featuring three-proofing coating (anti-mildew, anti-humidity, and anti-salt spray).
- Easy Installation: Standard rail-style (DIN-rail) mounting ensures stability and space-saving in industrial control cabinets.
- Remote Reliability: Supports remote firmware upgrades and mechanisms for TCP/UDP link maintenance (Heartbeat/Registration packets).
Download Datasheet
AT command
manual
NetAssist
XCOM
configuration tool
Virtual serial port
Serial port server firmware update package
Company Proflile
Application
1: Harsh Industrial Sewage Treatment Monitoring
In wastewater treatment plants, high humidity and corrosive salt spray often lead to premature failure of networking hardware. The NA111 features an internal Three-Proofing Coating (anti-mold, anti-humidity, and anti-salt spray), ensuring the RS485-to-Ethernet link remains stable for years. This protection solves the frequent device replacement issue in humid, corrosive environments while maintaining reliable data telemetry from water quality sensors to the central PLC.
2: Retrofitting Legacy Factory Equipment for Cloud Connectivity
Many industrial automation integrators struggle with connecting old RS485-based PLCs to modern cloud platforms. The NA111-A simplifies this by integrating MQTT (MQTTC) and HTTP gateways directly into the hardware. By using the module's AC 85-265V wide voltage input, engineers can tap directly into the machine's main power line, enabling legacy equipment to report operational status to Alibaba or AWS clouds without adding external DC power converters.
3: High-Density Distribution Cabinet Space Optimization
In modern smart building power distribution cabinets, space is at a premium. The NA111-M version offers an ultra-compact footprint (932827mm) without sacrificing performance. Its standard DIN-rail mounting allows it to snap directly alongside circuit breakers. This compact design allows integrators to fit multiple serial servers into a single cabinet for multi-channel Modbus RTU to Modbus TCP conversion, optimizing the link budget for complex energy management systems.
Frequently Asked Questions
Q: Can the NA111 series handle high-frequency concurrent polling in a multi-host Modbus environment?
A: Yes, the NA111 supports multiple Modbus gateway modes, including a storage-type gateway and multi-host arbitration. When multiple TCP masters (e.g., a local HMI and a remote SCADA) attempt to access the same RS485 slave, the server internally manages the request queue and UART timing. It waits for the specified response interval or timeout before processing the next packet, preventing data collisions on the half-duplex RS485 bus and ensuring consistent Modbus RTU to TCP mapping.
Q: How does the "Three-Proofing Coating" specifically protect the internal circuitry under thermal stress?
A: The industrial-grade coating used on the NA111-M and NA111-A creates a high-insulation barrier that resists environmental degradation without trapping heat. In industrial environments ranging from -40°C to +85°C, this layer prevents the accumulation of conductive moisture and salt particles on fine-pitch IC pins (like the Ethernet controller). This mitigation is critical for preventing parasitic leakage currents and short circuits that often cause unexplainable reboots or packet loss in standard serial servers.
Q: What is the maximum cable length supported for the RS485 interface, and are termination resistors required?
A: While the NA111 is rated for long-distance data transmission, for bus lengths exceeding 200 meters or when operating at high baud rates, it is mandatory to match the characteristic impedance. The RS485 interface typically requires a 120-ohm termination resistor at both ends of the segment to minimize signal reflections at high-frequency transition edges. This reduces jitter and ensures that the UART-to-Ethernet frame synchronization remains accurate across the full 50-ohm to 120-ohm impedance range of industrial twisted-pair cabling.
Q: Can the device maintain connection stability if the ISP dynamic IP changes or the network drops temporarily?
A: The NA111 family incorporates several reliability mechanisms, including TCP/UDP Heartbeat packets and Registration packets. For dynamic network environments, it supports DHCP for automatic IP acquisition and DNS for domain name resolution. If the TCP link is severed, the module's keep-alive mechanism will automatically attempt to re-establish the socket based on the user-configured retry intervals, ensuring that the serial device remains "always-on" for IoT cloud reporting.
