5.14. Modem installation and configuration

Working with a modem includes a stage of its installation that is performed once and operations that are performed during each communication session. The modem installation is understood as its physical and software connection.

The method of physical connection is determined by the type of modem. The modem can be internal or external. The internal modem is a card that is inserted into the expansion slot on the motherboard. When it is applied, an additional asynchronous (COM) port is created. Setting up this port may require some professional user experience. In this case, the modem is not transportable. The advantages of an internal modem are its cheapness, and the fact that it does not require a separate connection to the electrical network, does not use the COM port, and is ready for work immediately after turning on the computer.

External modems are autonomous devices that are connected by special cables to a PC through asynchronous ports. For this type of modem you need to connect to the mains, most often through the voltage converter attached to it.

Both types of modem with a physical connection can be interfaced with a voice telephone. The following connection methods are available:

• the modem is connected to the telephone jack and the phone is connected to the modem;

• both the telephone and the modem are connected to the telephone jack through a connector on it.

Connection to the subscriber with both methods of connection is carried out using both the telephone and the modem. The active (occupying the line) is only the device (modem or telephone) from which the first to start dialing the phone number. In the switching programs using the first method of connection, you can talk on the phone and without breaking the connection, transfer control to the modem, after which, putting the handset, you can perform a modem connection session. This connection method is convenient when you first need to call the subscriber in order to alert him about the beginning of the session and negotiate the communication parameters. But the second way to pair the modem and telephone, as well as the presence of a parallel telephone or fax machine makes the modem's operation worse.

The modem in Windows is programmatically connected to the OS as a new device. A software connection is made using the New Device Connection Wizard, which is caused by the command *** Control Panel / Hardware Installation / Modem. The brand of the modem is specified by the user in the list of modems recognized by the OS, or it is automatically detected. When modem drivers are supplied by the manufacturer, it is installed in the usual way: by clicking the Install button from disk or using the installation program using the Start / Run command. After the modem is programmatically connected in Windows, you can configure its parameters by performing the following sequence of actions:

1) activate the My Computer / Control Panel / Modems icon;

2) select a specific modem in the Modems window that opens by clicking the Properties button;

3) set the required values ​​of the configuration parameters of the modem operation in the fields of the General and Connection tabs.

The speed of the port characterizes the speed of information exchange between the PC and the modem. In this case , the port speed is set in the Highest speed field on the General tab of the Modem Properties window. If it is necessary to limit the transmission speed on the line, then reduce the speed on the port, but the connection settings in the Connection tab do not change.