A wireless modem is a computer hardware that translates a computer's digital signal into analog signals that can be transmitted along an ordinary telephone line, which can be received by another modem at the other end of the line and translated into a computer-readable Language. This simple process completes the communication between two computers.
The modem in English is MODEM, its role is analog signal and digital signal "translator". Electronic signal is divided into two kinds, one is "analog signal", one is "digital signal". We use the telephone line to transmit analog signals, and PC is the transmission between the digital signal. So when you want to connect your computer to the Internet via a telephone line, you must use a modem to "translate" two different signals. When the Internet is connected to the Internet, when the PC sends information to the Internet, because the telephone line is an analog signal transmission, it is necessary to use a modem to "translate" the digital signal into an analog signal to be transmitted to the Internet. " When the PC from the Internet to obtain information, because the message from the Internet through the Internet is the analog signal, so the PC want to understand them, but also must use the modem "translation", this process is called "demodulation" The In general it is called "modulation and demodulation".
USB interface for modems
The emergence of USB technology, to the computer peripherals to provide faster, more simple way to connect, SHARK company introduced the first USB interface 56K modem, this only the size of the modem call to the traditional serial modem to bring a challenge The Just connect it to the host's USB interface, usually on the host has two USB ports, and USB interface can connect 127 devices, if you want to connect multiple devices can also buy USB hub. Usually USB monitors, printers can be used as USB hub, because they have in addition to the host USB interface, but also provides 1-2 USB interface.
1. External Modem installation:
Step 1: Connect the telephone line. Plug the RJ11 plug of the telephone line into the Modem interface of the Modem and connect the Modem's Phone interface to the telephone.
Step 2: Turn off the computer, connect one end of the cable (25-pin male) to the modem, and the other end (9-pin or 25-pin plug) to the COM port on the host.
Step 3: Connect the power transformer to the POWER or AC interface of the modem. When the power is turned on, the modem's MR indicator should be on.
If the MR lamp is off or flashing, it indicates that it is not installed properly or the modem is faulty. For the voice function of the Modem, Modem should also be the SPK interface and the sound card Line In interface connection, of course, can also be directly connected with the headset and other output devices.
In addition, Modem's MIC interface is used to connect an electret microphone, but it is best to connect the microphone to the sound card.
2. Built-in Modem installation:
The first step: according to the instructions of the instructions, set the relevant jumper. Since COM1 and COM3, COM2 and COM4 share an interrupt, it can usually be set to COM3 / IRQ4 or COM4 / IRQ3.
Step 2: Turn off the computer and open the chassis, the Modem card into the motherboard any vacant expansion slot.
Step 3: Connect the telephone line. Plug the RJ11 plug of the telephone line into the Line interface on the Modem card, and then use the telephone line to connect the Phone interface on the Modem card to the telephone. At this point pick up the phone, should be able to call the normal.
Foreign Modem is not necessarily better than the domestic, many people like to buy foreign brands Modem. In fact, most of those Modem makers in Taiwan Province, the production, but in the choice of materials on the more fills. While the domestic Modem products in the design to take into account the actual situation in the country, the price is cheaper, and in terms of performance is not worse than the foreign products Do not pay attention to appearance, the key to see the internal quality. Modem shell on the market engage in more and more flowers, the color is more and more brilliant, but you do not be in the purchase when the appearance of the confusion. Many manufacturers introduced the so-called series of products, the price difference is very large, but in fact use the same circuit board, but the shell is different. Buy Modem is not necessary for the shell and spend hundreds of dollars more money.
USB interface, external Modem, USB interface, external Modem Most of the soft "cat", it is small, no external power supply, and can be hot-swappable, a lot of advantages. But many of the USB interface Modem connection rate is too low, many even 50K can not be achieved. And some USB interface Modem in the dial when the problem will occur, so it is best to buy a serial interface external Modem better. Low-cost Modem performance is not necessarily poor. The market price of the cheapest 56K external Modem price is only about 350 yuan, Superman own use is this price is only 300 yuan TP-LINK 56K "cat". Used for a year or so, the drop is definitely not as frequent as the legend. The only problem is that the connection speed is only 48K.