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ATX power supply etc -- Jaycar datasheets --

 

RJ45, Cross Over and Patch cable Pin Outs

DB9 & DB25 Pin Outs

 

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RJ45 Plug pin outs:

MDIX Cross over cable (MDIX - MDIX)
CROSS NORMAL

Pin

Colour Colour
1 Orange / White Green / White
2 Orange Green
3 Green / White Orange / White
4

Blue

Blue
5 Blue / White Blue / White
6 Green Orange
7 Brown / White Brown / White
8 Brown Brown

Note: for normal patch cable use the above "Normal" pin outs at both ends of cable.

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The RS-232C Interface

DB9 and DB25 pin outs:
SIGNAL NAME PIN No. (9 PIN) PIN no. (25 PIN)
TD Transmitted Data 3 2
RD Received Data 2 3
RTS Request to Send 7 4
CTS Clear to Send 8 5
DSR Data Set Ready 6 6
SG Signal Ground 5 7
CD Carrier Detect 1 8
DTR Data Terminal Ready 4 20
RI Ring Indicator 9 22

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Common RS232 Connections

Each signal (except ground) is either an input or an output depending whether it is on the Data Terminal Equipment 'DTE' (e.g. a computer terminal) or the Data Circuit Terminating Equipment 'DCE' (e.g. a modem). A typical connection is shown above.

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When two computer terminals (DTEs) are connected together a 'null modem' hook-up is needed to fool each DTE into thinking that it is connected to DCE. A typical null modem connection is shown above.

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