Sun Microsystems enterprise server 220r User Manual
Appendix A
Connector Signal Descriptions
157
Reference for the Serial Port A and B
Connectors
Connectors
The serial port A and B connectors (J2902 and J2903, respectively) are DB-25 type
connectors located on the main logic board back panel. Both serial ports conform to
RS-423/RS-232 specifications.
connectors located on the main logic board back panel. Both serial ports conform to
RS-423/RS-232 specifications.
Serial Port A and B Connector Diagram
Serial Port Signals
Pin
Mnemonic
Signal Name
Description
1
Not connected
None.
2
TXD
Transmit Data
Used by the data terminal equipment (DTE)
to transmit data to the data circuit
equipment (DCE). Except when control data
is being sent, RTS, CTS, and DCD must be
ON for this line to be active.
to transmit data to the data circuit
equipment (DCE). Except when control data
is being sent, RTS, CTS, and DCD must be
ON for this line to be active.
3
RXD
Recieve Data
Used by the DCE in response to received
data from the DTE.
data from the DTE.
4
RTS
Ready to Send
Used by the DTE to condition the DCE for
data transmission. The transition to ON
directs the DCE to go into transmit mode.
The transition to OFF directs the DCE to
complete the transmission.
data transmission. The transition to ON
directs the DCE to go into transmit mode.
The transition to OFF directs the DCE to
complete the transmission.
1
13
25
14
1
13
25
14
Serial port B
Serial port A