Instruction Manual

Connecting a Modem

The SVxx53DXI will work with virtually any Hayes-compatible modem that recognizes the standard AT command set. Some modem manufactur- ers offer “enterprise” grade modem products that include technology to improve the stability of connections; whether this type of product would be beneficial 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 offer “56K” (or 56,000 bps) con- nections 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 technol- ogy, 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 reflect the line conditions at the time the connection is made.

The serial port can be used for serial port configuration when the modem

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