Moxa NPort 5250A 2-Port RS-232/422/485 Device Server

Technical Overview

The Moxa NPort 5250A device server is designed to instantly make serial devices network-ready, enabling PC software direct access to serial devices from anywhere on the network. This ultra-lean, ruggedized, and user-friendly solution provides simple and reliable serial-to-Ethernet connectivity. It features comprehensive surge protection for serial, Ethernet, and power lines, compliant with IEC 61000-4-5 standards. The NPort 5250A supports two RS-232/422/485 serial ports and one 10/100BaseT(X) Ethernet port, offering versatile TCP and UDP operation modes. Dual DC power inputs ensure continuous operation, while its compact metal housing allows for desktop, DIN-rail, or wall mounting, making it suitable for demanding industrial environments.

Key Features

Fast 3-step web-based configuration for easy setup.
Surge protection for serial, Ethernet, and power lines (IEC 61000-4-5 compliant).
COM port grouping and UDP multicast applications.
Screw-type power connectors for secure installation.
Dual DC power inputs (power jack and terminal block).
Supports versatile TCP and UDP operation modes.
Rugged metal housing for industrial environments.
Supports standard baudrates from 50 bps up to 921.6 kbps.
Real COM/TTY drivers for Windows, Linux, and macOS.
Low power consumption with a built-in MiiNe SoC.
1.5 kV magnetic isolation protection for Ethernet.

Technical Specification Matrix

Parameter	Value
Input Voltage	12 to 48 VDC
Input Current	119 mA @ 12 VDC
Operating Temperature	0 to 60°C (32 to 140°F)
Storage Temperature	-40 to 75°C (-40 to 167°F)
Ambient Relative Humidity	5 to 95% (non-condensing)
Ethernet Ports	1 x 10/100BaseT(X) (RJ45 connector)
Serial Ports	2-port RS-232/422/485 (DB9 male connector)
Baudrate	50 bps to 921.6 kbps
Magnetic Isolation Protection	1.5 kV (built-in)
Surge Protection	IEC 61000-4-5 compliant (Serial, Ethernet, Power)
Housing Material	Metal
Safety Certifications	UL 60950-1, IEC 62368-1, EN 62368-1, CE, FCC, DNV
Installation	Desktop, DIN-rail mounting (with optional kit), Wall mounting

Industrial Applications

1. Industrial Process Control & Monitoring

Connects legacy serial-based sensors (e.g., pressure transducers, flow meters) and actuators to modern Ethernet-based SCADA or control systems in factory environments.

Problem Solved

This device overcomes the distance limitations and point-to-point nature of serial communication by converting RS-232/422/485 signals to Ethernet, enabling centralized monitoring and control over IP networks. Its 0 to 60°C operating temperature range, metal housing, and IEC 61000-4-5 compliant surge protection ensure reliable operation and protection against electrical transients in harsh factory settings.

SCADAPLCModbusRS-485EthernetIndustrial IoTData AcquisitionDistributed ControlSurge Protection0-60°C

2. Building Automation Systems (BAS) & Access Control

Integrates serial devices such as card readers, payment terminals, and HVAC control units into a building's IP network for centralized management and enhanced security.

Problem Solved

The NPort 5250A facilitates remote management and data logging for various building utilities and access points by bridging their serial interfaces to the network. Its compact dimensions allow for discreet installation, while dual power inputs provide redundancy for critical security and environmental controls, ensuring system uptime even during power fluctuations.

HVACAccess ControlCard ReadersPayment TerminalsIP NetworkRS-232Data LoggingRedundant PowerNetwork Integration

3. Utility and Power Automation Systems

Enables communication between serial-based protective relays, remote terminal units (RTUs), and energy meters in substations or power distribution networks with a central control center via Ethernet.

Problem Solved

This device provides robust and secure serial-to-Ethernet conversion crucial for critical infrastructure where electrical noise and potential surges are prevalent. The IEC 61000-4-5 compliant surge protection on serial, Ethernet, and power lines is vital for preventing damage and ensuring reliable data transmission in electrically harsh environments, enabling real-time monitoring and control of power assets.

Substation AutomationRTUEnergy MeteringProtective RelaysSurge ProtectionElectrical NoiseRemote MonitoringPower Distribution