RS232 Female to Female Crossover Cable – Trusted DB9 9-Pin F-F 23 Null Modem, 1.5–5m | DTECH DT-9006C

An RS232 female to female crossover cable is the solution when you need to join two male-terminated RS-232 cables or devices with null modem (crossed TX/RX) wiring. The DTECH DT-9006C provides dual DB9 female sockets connected by a 23 crossover internal wiring sequence, built with a tinned copper core, nickel-plated connectors and an environmentally friendly PVC jacket — making it a precise, professional tool for direct serial communication between DTE devices.

Who Needs a Female-to-Female 23 Crossover Cable?

In RS-232 serial connectivity, the gender and wiring of a cable must both match the application. The DT-9006C combines F-F gender (female sockets on both ends, accepting male DB9 plugs) with 23 crossover wiring (Pin 2 and Pin 3 crossed). This combination serves two specific scenarios. First, as a null modem coupler: joining two male-terminated serial cables where crossed TX/RX is also required — for example, extending a null modem connection across a longer distance using two separate cable runs. Second, for connecting two devices that both expose male DB9 serial ports and require direct DTE-to-DTE communication with null modem wiring, such as two PCs or a PC and an industrial controller communicating directly without a modem. As specified in the TIA/EIA RS-232 standard, both devices must transmit on Pin 3 and receive on Pin 2 for standard DTE RS-232 operation — the 23 crossover ensures each device’s TX feeds the other device’s RX correctly. Always confirm your device’s required wiring method from its manual before purchasing.

23 Crossover vs Full Crossover

The DT-9006C uses a 23 crossover wiring sequence: only Pins 2 and 3 are swapped, with Pin 5 (GND) connecting straight through. This is a simple null modem configuration — sometimes called a 3-wire null modem — that suits most direct serial communication applications without hardware handshaking. If your devices require a full crossover with additional handshaking signals (DTR/DSR, RTS/CTS), a full null modem cable is required instead. Check your device documentation to confirm which null modem configuration applies.

Construction That Lasts

The tinned copper core inside the DT-9006C resists oxidation far better than bare copper, maintaining consistent signal quality across the cable’s operational life. This matters in environments with humidity variation or temperature cycling — server rooms, factory floors, outdoor enclosures and industrial control panels where bare copper would corrode and increase resistance over time. Nickel-plated DB9 female connector shells resist surface corrosion and maintain a firm mechanical grip on male DB9 plugs through repeated connection cycles. The environmentally friendly PVC jacket is flexible for easy routing through cable trays and panels while remaining durable under daily professional use.

5 Length Options Including 2.5m

Unlike most serial cables in this range, the DT-9006C is available in five lengths: 1.5m, 2m, 2.5m, 3m and 5m. The 2.5m option is particularly useful where standard 2m falls just short of a rack-to-device run but a full 3m would create excess cable slack. Choose the length that fits your installation cleanly.

Applications

Linking two male-terminated null modem cable segments into a longer crossover run, connecting PCs and industrial PCs in direct serial communication, serial console access to routers and managed switches, PLC and CNC programming via RS-232, legacy null modem file transfers, and any application requiring a null modem F-F coupler with crossed TX/RX.

For M-M and M-F variants of the 23 crossover RS232 cable, see our RS232 crossover cable range at bam.ae. Browse the complete industrial serial product range for converters, adapters and serial Ethernet servers.

Specifications Table