3.15 How to Set the 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-432 or EIA-232D signal levels. EIA-432 levels are the default standard for North American users. EIA-232D levels are required for digital telecommunication in nations of the European Economic Community.

For further information, see your Sun Enterprise 220R Server Owner's Guide.

3.15.1 Before You Begin

Complete these tasks:

• "2.1 How to Power Off the System"

• "2.4 How to Position the System for Service"

• "2.6 How to Remove the System Cover"

• "2.8 How to Avoid Electrostatic Discharge"

3.15.2 What to Do

1. Locate the jumpers on the main logic board.

   A main logic board jumper is identified by its jumper address, labeled on the board with the letter "J" followed by four numbers (JXXXX). Jumper pins are located immediately adjacent to the jumper address. On the board, pin 1 is marked with an asterisk.

2. Set the main logic board serial port jumpers J2604 and J2605.

   Using long-nose pliers, place a shunt over the appropriate pins according to the following table.

   Serial port jumper	A shunt on pins 1 and 2 selects	A shunt on pins 2 and 3 selects	The default shunt is on pins
   J2604	RS-232D	RS-432	2 and 3
   J2605	RS-232D	RS-432	2 and 3

3.15.3 What Next

Complete the following task to reassemble the system:

• "2.7 How to Replace the System Cover"