About Serial Port Jumpers - Sun Microsystems Enterprise 250 Owner's Manual

About Serial Port Jumpers

The serial port jumpers on the main logic board (J2604 and J2605) permit the
configuration of the system's two serial ports for either EIA-423 or EIA-232D signal
levels. EIA-423 levels are the default standard for North American users. EIA-232D
levels are required for digital telecommunication in nations of the European
Community.
The figure below shows the jumper locations, and the table describes their function.
Figure 5–11
Sun Enterprise 250 Server Owner's Guide ♦ Revision A, June 1998
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