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Figure b-2 – Sun Microsystems Sun PCI High Speed Quad Port Serial Interface Adapter 819-1207-11 User Manual

Page 53

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Appendix B

Null Modem Cable Requirements

33

FIGURE B-2

illustrates a synchronous null modem cable that allows you to another

system, Sun or non-Sun, using the RS-449 interface. The Sun supplies both the
transmit and receive clocks for the other system. Note that this null modem cable is
not symmetrical.

FIGURE B-2

Null modem Cable (Sun System Supplies Clocking for Both Sides)

TxD (4,22)

RxD (6,24)

RTS (7,25)

CTS (9,27)

DSR (11,29)

SG (19)

DCD (13,31)

RxC (8,26)

DTR (12,30)

TxC (17,35)

Sun workstation

TxD (4,22)

RxD (6,24)

RTS (7,25)

CTS (9,27)

DSR (11,29)

SG (19)

DCD (13,31)

TxCI (5,23)

RxC (8,26)

DTR (12,30)

Sun or foreign
device

that supplies clocking