Special connection options for serial ports. Terminal Block and RJ45 adapters are intended for RS422 and RS485. The RJ45 adapters convert a DSub9 male serial port to Cat5 cable. This way it is easy to establish a high-quality connection for RS422 and RS485. At the far end the other adapter converts back from Cat5 to a DSub9 male port. Signals for RS485 and RS422 are transmitted via twisted pairs in this connection. It is also usable for RS232, within the normal distance limits. Null-Modem adapters for RS232 convert from male to female pinout and vice versa.