Eaton U209-18N-NULL Tripp Lite USB Null Modem Serial FTDI Adapter Cable COM Retention USB A
The Eaton U209-18N-NULL Tripp Lite USB to Null Modem Serial FTDI Adapter Cable converts a USB-A port into an RS-232 null modem serial port. It features a USB-A male connector, DB9 female connector, integrated FTDI FT232RL chipset, and an 18-inch cable length for connecting compatible DTE serial equipment to a computer, laptop, or tablet.
USB to RS-232 Null Modem Conversion
The U209-18N-NULL is designed specifically for RS-232 null modem connections. Its integrated null modem configuration addresses DCE/DTE connection requirements without requiring an additional cross-wired serial cable or adapter.
FTDI Chipset and COM Retention
An integrated FTDI FT232RL chipset provides the USB-to-serial interface, with support for data transfer rates up to 256 Kbps. COM Retention automatically reassigns the same COM port values after the adapter is disconnected or the computer is rebooted.
18-Inch Compact Cable
The 18-inch cable provides a short connection between a USB-A host and a DB9 serial device. The compact length can be useful for laptop-based service work and other installations where excess cable length is undesirable.
Shielding and Construction
The cable uses foil and braid shielding to reduce EMI/RFI interference. The connectors are nickel plated with gold-plated contacts, while integral strain relief and a flexible PVC jacket provide the cable construction specified by Eaton.
Key Features
- USB-A male to DB9 female RS-232 null modem connection
- Integrated FTDI FT232RL chipset
- Data transfer rates up to 256 Kbps
- COM Retention for maintaining assigned COM port values
- 18-inch cable length with foil and braid shielding
DC Supplies Product Note
The null modem configuration is the key distinction of the U209-18N-NULL: it is designed to resolve DCE/DTE connection conflicts directly, so a separate cross-wired serial cable or adapter is not required for the supported connection.
Typical Applications
- Connecting RS-232 serial equipment to USB-A computers
- Serial device configuration and maintenance
- Laptop-based service and field work
- Connecting DTE serial devices through USB
- Legacy RS-232 equipment using null modem connections
Operating System Compatibility
Eaton specifies compatibility with Windows, Mac, and Linux operating systems. The owner’s manual also identifies Android compatibility for supported host devices.
Technical Specifications
| Specification | Details |
|---|
| Brand | Eaton / Tripp Lite |
| Part Number / MPN | U209-18N-NULL |
| Product Type | USB to RS-232 Null Modem Serial Adapter Cable |
| USB Specification | USB 2.0 |
| USB Connector | USB-A Male |
| Serial Connector | DB9 Female |
| Serial Interface | RS-232 Null Modem |
| Chipset | FTDI FT232RL |
| Maximum Data Transfer Rate | 256 Kbps |
| Cable Length | 18 in (45.72 cm) |
| COM Retention | Yes |
| Power | USB Bus Powered |
| External Power Supply | Not Required |
| Shielding | Foil and Braid |
| Cable Jacket | Flexible PVC, VW-1 |
| Connector Plating | Nickel |
| Contact Plating | Gold |
| Color | Black / Silver |
| Number of Ports | 1 |
| Operating Temperature | 32°F to 104°F (0°C to 40°C) |
| Storage Temperature | 14°F to 131°F (-10°C to 55°C) |
| Operating Humidity | 5–90% RH, non-condensing |
| Power Consumption | 0.5W |
| Compliance | CE, REACH, RoHS, WEEE, FCC |
| Product Dimensions | 4.5 × 3.7 × 1.5 in |
| Product Weight | 0.001 lb |
| UPC | 037332198297 |
Package Contents
- 1 × Eaton U209-18N-NULL USB to Null Modem Serial FTDI Adapter Cable, 18 in
- 1 × Driver CD
- 1 × Owner's Manual
Frequently Asked Questions
What does the U209-18N-NULL connect?
It connects a USB-A host port to a DB9 female RS-232 null modem serial connection.
What is the maximum data transfer rate?
The U209-18N-NULL supports data transfer rates up to 256 Kbps.
Does this adapter require external power?
No. The adapter is USB bus powered and does not require an external power source.
What is COM Retention?
COM Retention automatically reassigns the same COM port values when the adapter is disconnected or the host system is rebooted.
What operating systems are supported?
Eaton specifies compatibility with Windows, Mac, and Linux. The owner’s manual also lists Android for supported applications.
Is this a standard USB-to-DB9 serial cable?
It is specifically configured as a USB-to-RS-232 null modem adapter. Its null modem configuration is intended to resolve supported DCE/DTE connection requirements without an additional cross-wired serial adapter.
