Sun Microsystems 220R - Manual (Page 233)

A.2.1 Serial Port A and B Connector Diagram
A.2.2 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.
3 RXD Recive Data Used by the DCE in response to received
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.
5 CTS Clear to send Used by the DCE to indicate if it is ready to
receive data from the DTE. When CTS, DSR,
RTS and DTR are ON, the DCE is ready to
transmit data received from the DTE across
the communications channel. When only CTS
is ON, the DCE is ready to accept dialing or
control signals only. When CTS is OFF, the
DTE should not transfer data across TXD.
Connector Signal Descriptions 233