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Hardware settings

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Hardware settings

The connection preferences for a modem provide hardware settings that determine how data is sent and reassembled by modems. To change hardware settings, see Change hardware settings.

Data bits

Data bits are the number of bits in a word. Most systems now use eight bits to represent a single data character (extended ASCII). In rare instances, some older systems still use seven bits.

Parity

Parity controls how modems check for errors. Line noise can insert extra bits into data being transmitted over a phone line. In older modulation types, parity checked for these errors. With parity checking, the transmitting modem adds a parity bit to the data packet in order to make the number of 1 bits in the packet odd or even. The receiving modem adds up the number of 1 bits that is received and accepts or rejects the packet depending on whether the sum agrees with the parity bit.

Several settings for parity are available:

Set this To do this

Even

Set the parity bit to 0 or 1 to make the number of 1 bits even.

Odd

Set the parity bit to 0 or 1 to make the number of 1 bits odd.

None

Send no parity bit.

Mark

Set the parity bit always to 1.

Space

Set the parity bit always to 0.

Most modem connections now use more reliable and sophisticated methods of error checking, so this is usually set to None.

Stop bits

Stop bits frame data packets in asynchronous communication. These tell the receiving modem that a byte has been sent. Modern asynchronous protocols never require more than one stop bit.

Modulation

In the hardware settings, modulation is the protocol that a modem uses to translate digital information to the audio tones transmitted over a standard telephone line. Both computers must be using the same type of modulation to exchange information successfully.

You can switch the modulation type to be compatible with the modem signals for the computer to which you are trying to connect. Most modems fall into the standard category, but if you are having trouble connecting, try switching to a nonstandard modulation type.