Serial null-modem cable InLine B-12222, 9-pin female to female, 2 m

InLine B-12222 is a 2-meter null-modem serial cable with DE-9 (9-pin) female connectors on both ends, designed to provide a direct RS-232 connection between two DTE devices. The cable swaps transmit and receive lines to enable peer-to-peer serial communication without the need for a modem or other intermediary device. It is intended for serial data transfer, device configuration, firmware updates, and diagnostics where a standard RS-232 null-modem link is required.

Advantages

This 9-pin female-to-female null-modem cable offers a simple, reliable physical connection for legacy and industrial equipment that use RS-232. Its 2 m length gives flexibility for desktop and rack environments while keeping signal integrity for short to moderate distances. The cable supports straightforward cross-over wiring so no adapters or custom wiring are necessary for common serial communication tasks. Build quality and standard DE-9 connectors ensure compatibility with a wide range of serial ports.

Suitable for (tasks / use cases)

• Direct serial communication between two computers or terminals without a modem
• Configuring routers, switches, industrial controllers, and other RS-232 devices
• Transferring data between legacy systems and modern PCs with DE-9 ports
• Performing firmware updates, diagnostics, and troubleshooting over RS-232

Key specifications

• Cable type: null-modem (crossed transmit/receive)
• Connector A: DE-9 (9-pin) female
• Connector B: DE-9 (9-pin) female
• Length: 2 m
• Signaling standard: RS-232
• Typical use: serial data transfer, configuration, diagnostics

How to use

Connect one DE-9 female end to the serial port of the first DTE device and the other end to the serial port of the second DTE device. Ensure both devices are powered and configured to use compatible serial parameters (baud rate, parity, data bits, stop bits, and flow control). For most uses the null-modem wiring handles RTS/CTS or DTR/DSR line crossing as required for basic communication; consult device manuals if hardware handshaking needs to be explicitly set. Once connected and configured, initiate the serial session using terminal software or the device's built-in communication interface.

Recommendations

Use the cable for short- to moderate-distance RS-232 links in controlled indoor environments. Avoid running the cable parallel to high-voltage power lines for long stretches to reduce potential interference. When connecting industrial equipment, verify grounding and shield continuity if available to minimize noise. If serial communication issues occur, confirm pinout compatibility and serial settings on both devices before assuming a cable fault.