DB9 RS232 Serial Null Modem Cable F/F 1 m, StarTech

The StarTech DB9 RS232 Serial Null Modem Cable F/F 1 m is a female-to-female DB9 cable engineered for RS232 serial communication where transmit and receive lines must be crossed. At 1 metre in length and finished in black, this cable facilitates direct device-to-device links between legacy serial equipment, PCs and embedded systems without requiring additional adapters. The cable is CE and RoHS certified and built to support reliable short-distance serial transfers and control signals.

Advantages

This null modem cable provides a straightforward way to establish bi-directional serial communication by reversing the transmit and receive wiring internally, eliminating the need for external adapters or null-modem boxes. The DB9 female connectors on both ends ensure compatibility with a wide range of 9-pin serial ports commonly found on industrial controllers, POS terminals and older computers. Its 1 m length balances flexibility and signal integrity for desktop and rack-mounted setups, while compliance with CE and RoHS addresses regulatory and environmental considerations.

Suitable for

• Connecting two PCs or terminals for direct RS232 file transfer or debugging
• Linking industrial controllers, PLCs or CNC devices that use DB9 serial ports
• Integrating POS systems, barcode scanners or receipt printers with serial interfaces
• Connecting embedded systems, development boards or diagnostic equipment

Key specifications

• Cable type: RS232 null modem, female-to-female DB9
• Connector gender: DB9 female on both ends
• Length: 1 metre
• Color: black
• Standards: RS232 signaling
• Certifications: CE, RoHS

How to use

Plug each DB9 female connector into the corresponding 9-pin serial port on the devices you wish to link. Ensure connectors are fully seated and secure any retention screws to prevent accidental disconnection. Configure the serial port parameters (baud rate, parity, data bits, stop bits, and flow control) on both devices to match. For direct PC-to-PC communication, use terminal software or a file-transfer utility that supports null modem connections and the chosen serial settings.

Usage recommendations

For reliable communication, use the cable for short-range connections up to desktop or rack distances; avoid routing near high-voltage or high-frequency equipment that could introduce interference. Confirm serial port settings and, if possible, test with loopback or diagnostic tools before deploying in critical systems.