BINARY - DB9 FEMALE TO RJ45 MODULAR ADAPTER WITH NULL Make your next install faster and neater by using this DB9-RJ45 adapter. Just make up a custom length network cable using Cat5e/6, then put an adapter on each end to convert from RJ45 to the appropriate gender DB9 connector. Note: Note, this adapter has female DB9 with a null modem pin-out configuration. DB9 Female to RJ45 Adapter | Null Modem Cable Pinout DB9 DB9 Female to RJ45 Modular Adapter wired with Null Modem pinout. Use Cat5e/6 cable to attach Connecting RS-232 equipment to a control system can sometimes require soldering or using cables that are too long for the job.