Sun Microsystems 220R manual Reference for the Serial Port A and B Connectors, Serial Port Signals

Reference for the Serial Port A and B 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.

Serial Port A and B Connector Diagram

13	1
Serial port B	14
25
13	1
Serial port A	14
25

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	Recieve 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.

Appendix A Connector Signal Descriptions 157