RS232 Full Crossover Cable – Full Handshaking DB9 9-Pin M-M Null Modem, 0.5–5m | DTECH DT-9007A

An RS232 full crossover cable is required when two serial devices need not only their transmit and receive lines swapped but also all hardware handshaking signals crossed — a configuration that goes beyond the simpler 23 crossover (null modem basic) wiring. The DTECH DT-9007A delivers this in a DB9 9-pin male-to-male format: TX/RX, RTS/CTS and DTR/DSR are all crossed end-to-end in a single cable. Built with a tinned copper core, nickel-plated connectors and an environmentally friendly PVC jacket, it is designed for professional serial communication in industrial, office and legacy computing environments.

What Does an RS232 Full Crossover Cable Actually Do?

In standard RS-232 wiring, a DTE device (a PC, PLC or controller) transmits data on Pin 3 (TXD), receives on Pin 2 (RXD), signals readiness via Pin 4 (DTR) and requests to send via Pin 7 (RTS). When two DTE devices are connected directly — without a modem — each device’s TX must reach the other’s RX, and each device’s handshaking outputs must connect to the other’s handshaking inputs. The DT-9007A achieves this by crossing Pin 2 ↔ Pin 3 (RXD/TXD), Pin 7 ↔ Pin 8 (RTS/CTS) and Pin 4 ↔ Pin 6 (DTR/DSR), with Pin 5 (GND) straight through. This allows both devices to negotiate and control data flow completely through hardware signals, with no risk of buffer overruns or lost data. As specified by the TIA/EIA RS-232 standard, these signals are defined precisely to support exactly this type of full-handshaking DTE-to-DTE connection. Always verify your device’s required wiring configuration from its manual before purchasing.

Full Crossover vs 23 Crossover — Which Do You Need?

The DTECH DT-9006A uses a 23 crossover configuration — it crosses only Pins 2 and 3 (TX and RX), with Pin 5 (GND) straight through. This works for devices that communicate over just three wires and do not rely on hardware handshaking signals. The RS232 full crossover cable is needed when a device uses RTS/CTS or DTR/DSR signals for flow control or connection verification — common in older industrial controllers, modems, barcode systems, data acquisition units and test equipment that require these signals to initiate or sustain communication. If your device works correctly with the 23 crossover, the DT-9006A is the right choice. If it does not, or if the manual specifies full null modem wiring, the DT-9007A is the cable you need.

Construction Built for Long-Term Reliability

Inside the DT-9007A, the tinned copper core prevents the surface oxidation that degrades bare copper over time, maintaining low contact resistance and signal integrity across years of use — important in environments with temperature cycling or humidity variation such as factory floors, server rooms and control cabinets. Nickel-plated DB9 connectors resist corrosion at the contact points and withstand repeated mating cycles without degradation. The environmentally friendly PVC outer jacket combines flexibility for routing in tight spaces with the durability required for professional daily use.

Plug-and-Play, Five Length Options

No drivers are needed. The DT-9007A supports the RS-232 serial protocol natively and is recognised immediately by Windows, Linux, macOS, SCADA platforms and industrial HMIs. Available in 0.5m, 1.5m, 2m, 3m and 5m — choose 0.5m for back-of-rack panel connections, or 3m/5m for spanning adjacent equipment bays.

Typical Applications

Direct PC-to-PC serial file transfer, industrial PLC and CNC serial port configuration, router and managed switch console access with full hardware handshaking, legacy modem communication, barcode reader and scanner integration, factory data acquisition equipment and any serial application where a full null modem crossover with RTS/CTS and DTR/DSR is required.

For the 23 crossover M-M variant (TX/RX only), see the RS232 M-M 23 crossover cable (DT-9006A). Browse the full industrial serial product range at bam.ae.

Specifications Table