Null Modem Cable InLine 9-pin Female–Female B-12225, 5 m

InLine Null Modem cable B-12225 is a 5 m, 9-pin female-to-female serial cable designed to connect two D-sub 9 RS-232 devices using crossed (null modem) wiring. It enables direct serial communication between two data terminal equipment (DTE) devices without requiring a modem or data communication equipment (DCE). The cable is intended for tasks such as data transfer, device configuration, debugging, and connecting legacy equipment that use the D-sub 9 serial interface.

Advantages

The B-12225 null modem cable provides a straightforward wired link for RS-232 serial communication over a 5 m length, avoiding network setup or intermediary modems. Female-to-female D-sub 9 connectors allow direct connection between two devices with 9-pin ports. Crossed wiring ensures the correct mapping of transmit and receive signals for peer-to-peer communication. The cable is compatible with standard D-sub 9 serial interfaces commonly found on industrial controllers, instrumentation, routers and older computing equipment.

Suitable for

• Data transfer between two RS-232 D-sub 9 devices
• Device configuration and firmware updates via serial console
• Debugging and serial logging for embedded systems and industrial equipment
• Connecting legacy PCs, printers, CNC controllers or instrumentation with 9-pin ports

Key specifications

• Connector type: D-sub 9, female to female
• Cable length: 5 m
• Wiring: crossed (null modem) for RS-232 signal mapping
• Signal standard: RS-232 serial communication
• Intended use: direct device-to-device serial connection without modem

How to use

Locate the two devices with D-sub 9 female serial ports that require a direct serial connection. Align and securely fasten the female-to-female cable using any adapter or gender-changer only if necessary for the specific device configuration; typically the cable connects directly to devices that expose male D-sub 9 connectors. Ensure both devices are powered off or in a safe state before connecting. After connecting, power the devices and configure serial port parameters (baud rate, parity, data bits, stop bits, flow control) on both ends to the same settings to establish communication. Use appropriate terminal software or device-specific tools to send and receive data.

Recommendations

For reliable RS-232 communication, set identical serial parameters on both devices and avoid routing the cable near strong sources of electromagnetic interference. Verify pinout compatibility with your equipment and, if necessary, use signal-grounding practices recommended by device manufacturers when connecting sensitive or industrial systems.