Owner's manual

Instruction Manual
49
Connecting a Modem
The SVxx53DXI will work with virtually any Hayes-compatible modem that recognizes
the standard AT command set. Some modem manufacturers oer enterprise” grade
modem products that include technology to improve the stability of connections;
whether this type of product would be benecial to your application depends on
whether you consider the modem connection to be mission-critical, the quality of your
telecom infrastructure, and your budget for implementing this solution. The model of
modem attached is essentially transparent to the SVxx53DXI.
It is important to note that modems that oer “56K” (or 56,000 bps) connections often
achieve connection speeds that are far lower than their maximum capabilities. Given the
limitations of telecom infrastructure (many locations have yet to implement fully digital
switching technology, and still rely on older analog technology for some segments), the
maximum “upstream” transfer rate is limited to a maximum of 33,600 bps between two
modems; the downstream rate is often within a similar range for a typical connection.
Therefore, speeds below 56,000 bps do not indicate a problem with the modem or the
SVxx53DXI, but simply reect the line conditions at the time the connection is made.
The serial port can be used for serial port conguration when the modem is connected.
It requires the use of a null modem serial cable.