General
Number of serial ports	8
RS-485 termination resistor	120 Ω
Air humidity	5–95 % nicht kondensierend
Offline buffer per port	64 KB

The Moxa NPort 6650-8-T is an industrial-grade terminal server with eight serial ports, designed for use in demanding environments such as power supply, transportation, or manufacturing facilities. The device enables the integration of serial devices into an Ethernet network and offers high reliability under harsh operating conditions. It supports serial interfaces RS-232, RS-422, and RS-485, with settings configurable individually per port. The baud rate is adjustable from 50 bps to 921.6 kbps, allowing flexible adaptation to various serial end devices.

Applications
The terminal server is designed for use in industrial environments, particularly in enclosures without climate control or in regions with extreme temperatures. It is suitable for applications requiring secure and stable communication between legacy systems and modern networks, for example in process automation, monitoring systems, or infrastructure monitoring. Support for IPv6 and redundant network functions such as STP, RSTP, and Turbo Ring (via NM module) enhances network security and availability.

Functions and Equipment in Detail
Each of the eight serial ports features an integrated 64 KB buffer, which temporarily stores data in case of a network failure and transmits it once the connection is restored. This ensures continuous data transmission even during brief network interruptions. The RS-485 interfaces can be operated with configurable resistors (termination: 120 Ω, Pull High/Low: 1 kΩ / 150 kΩ) to optimize signal integrity over long cables. The serial ports are accessible via RJ45 connectors (8-pin), enabling a standardized and robust connection.

Technology Explained Simply
The NPort 6650-8-T is powered via a DC input with a voltage range of 88 to 300 VDC, making it suitable for applications in high-voltage environments. Power consumption is approximately 200 mA at 88 VDC. The operating temperature ranges from -40 to +75 °C, enabling use in extreme climatic conditions. The device is housed in a metal housing designed for mounting in a 48,3 cm ( 19 inch ) rack. Dimensions are 440 x 195 x 44 mm (excluding mounting brackets), and the weight is approximately 3460 g.

Compatibility and Accessories
The device supports various network protocols such as DHCP, DNS, SNMP, HTTP(S), Telnet, and LLDP. For network security, TLS 1.2, SSHv2, AES-128/256, HMAC, and SHA-1/256/384 are integrated. Authentication is performed via local database, RADIUS, or TACACS+. Certifications include EMC/EMS according to IEC 61000-4-2 to -4-11, FCC Part 15B, EN 55032/35, safety according to UL 60950-1 and NEMA TS2, as well as vibration tests according to IEC 60068-2-6 / -34. Environmental compliance is ensured by RoHS, CRoHS, and WEEE. The MTBF is 501,171 hours according to Telcordia standard.

Mounting and Installation
Mounting is done in a 48,3 cm ( 19 inch ) rack using the included rack mounting brackets. Installation requires connecting serial devices via RJ45 cables (DB9 connector to RJ45) to the respective ports of the terminal server. The network connection is made via the integrated 10/100BaseT(X) Ethernet port with Auto MDI/MDI-X. Configuration can be performed via web interface (HTTPS), Telnet, or SSH. The quick start guide included in the package supports setup.

Operational Advantages
The terminal server offers high operational reliability due to its wide voltage range, robust construction, and integrated security functions. Offline data storage ensures reliable data transmission even during brief network interruptions. Support for IPv6 and redundant network functions increase flexibility and availability in industrial applications. Certifications and high MTBF underscore the device’s reliability in critical applications.

Scope of Delivery
The scope of delivery includes the NPort 6650-8-T terminal server, two rack mounting brackets, a DB9 connector to RJ45 cable, a quick start guide, and a warranty card.