Serial adapter DIGITUS 10070136, 1x D‑SUB 25‑pin female to 1x D‑SUB 9‑pin male

The DIGITUS serial adapter converts a 25‑pin D‑SUB female connector to a 9‑pin D‑SUB male connector, providing a compact hardware interface for RS‑232 serial communication. It allows direct connection between devices that use different D‑SUB formats, enabling data exchange between legacy computers, industrial controllers, instrumentation and other serial peripherals without the need for additional cables or configuration. The adapter is a passive converter that preserves signal wiring for standard serial lines and is intended for straightforward physical interfacing in environments where pinout compatibility is required.

Advantages

The adapter offers a space-saving mechanical solution to connect D‑SUB 25‑pin and 9‑pin devices, eliminating the need to rewire or fabricate custom cables. Its passive design requires no power or software and maintains a simple and predictable signal path for RS‑232 lines. The small form factor makes it convenient for lab benches, equipment racks and mobile setups where temporary or permanent connections between different serial port types are necessary.

Suitable for

• Connecting legacy RS‑232 equipment with D‑SUB 25‑pin ports to modern or compact devices that use D‑SUB 9‑pin ports
• Linking industrial controllers, PLCs or CNC systems to terminal devices or PCs for configuration and data transfer
• Interfacing measurement instruments and laboratory gear with serial ports of differing D‑SUB sizes
• Temporary field connections, test rigs and service benches where quick port conversion is needed

Key specifications

• Connector A: 25‑pin D‑SUB female
• Connector B: 9‑pin D‑SUB male
• Interface standard: RS‑232 (serial signal levels)
• Construction: passive adapter, no active electronics or power required
• Form factor: compact, lightweight metal/plastic shell (manufacturer typical construction)

How to use

To use the adapter, align the 25‑pin female housing with the mating 25‑pin male connector of the equipment and secure any thumbscrews or fastening hardware if present. Plug the 9‑pin male end into the corresponding 9‑pin female port on the second device. No configuration or drivers are required at the adapter level; ensure both devices are using matching serial settings (baud rate, parity, data bits, stop bits and flow control) and that the pinout mapping is compatible for the intended signals. Inspect connections for firm seating and check cable shielding or grounding if communication issues occur.

Recommendations

Confirm the RS‑232 pinout compatibility of both devices before using the adapter. For environments with electrical noise or long cable runs, use properly shielded cables and grounding practices. Do not expect signal level conversion beyond RS‑232; if voltage level shifting, null‑modem crossover, or active signal conditioning is required, use an appropriate converter or adapter designed for those functions.