HP AD278A and AD279A PCI Multiplexer Support Guide, November 2008

Table B-6 RJ-45 Pin Assignments
Pin #DTE UseDescriptionSignal
1InputRing IndicatorRI
2InputData Set ReadyDSR
3OutputRequest to SendRTS
4N/AChassis GroundGND
5OutputTransmitted DataTXD
6InputReceived DataRXD
7ReferenceSignal GroundSG
8InputClear to SendCTS
9OutputData Terminal ReadyDTR
10InputData Carrier DetectDCD
RJ45 8-Pin Plug Hardware Handshaking (DTR) Cable
Using an 8-pin plug, the cable wiring shown in Table B-7, is sufficient for a terminal, printer, or
other DTE devices configured for DTR (hardware) flow control. However, some terminals and
printers may use a signal other than DTR for flow control. In addition, some terminals and
printers may have other cable requirements. Consult your terminal or printer manual for this
information. For universal compatibility, use the RJ-45 10-wire terminal/printer cable or a RJ-45
to DB-25 adapter.
Table B-7 lists the pin-out conenction between the RJ-45 8-pin adapter and the DB25
terminal/printer with DTR handshaking.
Table B-7 Terminal/Printer Cable with DTR Handshaking
DB-25 Male (Peripheral)RJ-45 8-Pin Plug (MUX Port End)
SignalPinPinSignal
RxD3Connected to4TxD
TxD2Connected to5RxD
DTR20Connected to7CTS
SG7Connected to6SG
GND1 (or shell)Connected (via
shield) to
3GND
RTS+CTS4+5Jumpered
IMPORTANT: Some terminal or printer manufacturers may use different methods of flow
control. Consult your documentation for specific wiring requirements.
RJ-45 8-Pin Plug Hardware Handshaking (RTS/CTS) Cable
Using an 8-pin plug, the cable wiring shown in Table B-8 is sufficient for a terminal, printer, or
other DTE devices configured for RTS/CTS (hardware) flow control. However, some terminals
and printers may have other cable requirements. Consult your terminal or printer manual for
this information. For more universal compatibility, use the RJ-45 10-wire terminal/printer cable
or a RoHS RJ-45 to DB-25 adapter.
Table B-8 lists the pin-out connection between the RJ45 adapter and the DB-25 terminal/printer
with RTS/CTS handshaking.
36 Peripheral Connections