ZyXEL Elite 2864 User Guide - Page 221

Chapter 21 ZyXEL MODEMS AND A PC All of the modems of the 2864 series may be used with a PC. If you install the internal PC card model, you don't need a serial cable. The modem's standard profiles should be just fine with most applications. If you are connecting to the modem's parallel port, make sure that you have a bidirectional PC parallel port and use a 25-wire cable to make the connection. The ZyXEL serial/parallel adapter card provides you with a special high-speed PC-modem communication advantage when working with a 2864 series modem. Serial Cable Most PCs are equipped with more than one serial port. Standard cables are readily available from many suppliers. Usually, serial ports are manufactured in two forms, either with a 25-pin male jack or a 9-pin male jack. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 12 3 4 5 6789 Fig. 21.1: 25-pin and 9-pin male connectors usually found in PCs. To connect a PC to the modem, you need the following 9-wire cable: Computer 9-pin 25-pin 1 8 2 3 3 2 4 20 5 7 6 6 7 4 8 5 9 22 Signal CD RXD TXD DTR Signal Ground DSR RTS CTS RI Modem 8 3 2 20 7 6 4 5 22 21-1