'D' Connectors

Description | Applications | Pin Assignments | Assembly Instructions

Description

Push-fit multiway connector used mainly on computer equipment. So called due to the 'D' shape of the shell. Available in 9, 15, 19, 23, 25, 37 and 50-way versions. 15-way high density types have 15 pins in a 9-way sized shell. Cable mounted connectors are normally made by fitting a cover to a chassis-mount connector. PCB mounting and IDC connectors are also available.

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Typical Applications

Computers & Peripherals - Serial, Parallel, Monitor & Games connections

Other applications where a low voltage multi-way connector is required.

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Pin Assignments

More pin assignment details will be added soon.

RS232C Serial Ports (9-pin & 25-pin):

There are 2 types of RS232C ports, DTE (Data Terminal Equipment) and DCE (Data Communications Equipment). The difference between them is the connections in the plug / socket - the TXD and RXD lines, and the handshake lines, are reversed. Serial ports are normally of the DTE type and modems etc. should have DCE ports. However serial printers often have DTE types. To connect a DTE port to a DCE port a straight through lead is needed, i.e. pin 1 to 1, 2 to 2 etc. To connect 2 DTE or 2 DCE ports, a cross-connected lead is required, called a null modem lead. If in doubt just try both and see which works. Handshaking connections can also cause additional problems. The table below shows the connections for 9 way and 25 way DTE and DCE ports:

	DTE		DCE
Function	9-pin	25-pin	9-pin	25-pin
TXD	3	2	2	3
RXD	2	3	3	2
RTS	7	4	8	5
CTS	8	5	7	4
DSR	6	6	4	20
DTR	4	20	6	6
DCD	1	8
RI	9	22
GROUND	5	7	5	7
SHIELD GROUND	CAN *	1	CAN *	1

* - This should be connected to the screen of the connecting cable.

For a straight lead, connect pin 1-1, 2-2 etc. For a null modem lead, connect as follows:

9-pin to 9-pin: 2 to 3, 3 to 2, 4 to 6+1, 5 to 5, 6+1 to 4, 7 to 8, 8 to 7.
25-pin to 25-pin: 2 to 3, 3 to 2, 20 to 6+8, 7 to 7, 6+8 to 20, 4 to 5, 5 to 4.
9-pin to 25-pin: 2 to 2, 3 to 3, 4 to 6+8, 5 to 7, 6+1 to 20, 7 to 5, 8 to 4.

Parallel Port (Bi-directional, 25-pin):

Pin	Direction (From Computer)	Function
1	Out	Strobe
2	Bi-directional	Data 0
3	Bi-directional	Data 1
4	Bi-directional	Data 2
5	Bi-directional	Data 3
6	Bi-directional	Data 4
7	Bi-directional	Data 5
8	Bi-directional	Data 6
9	Bi-directional	Data 7
10	In	Acknowledge
11	In	Busy
12	In	Error
13	In	Select
14	Out	Autofeed
15	In	Fault
16	Out	Initialise
17	Out	SelectIn
18-25	N/A	Ground

Older computers with uni-directional parallel ports use the same connections, however the data lines 0-7 are output-only.

Joystick / MIDI Port (15-pin):

Pin	Function
1	+5V DC
2	Button 1
3	Joystick 1 - X
4	Ground
5	Ground
6	Joystick 1 - Y
7	Button 2
8	+5V DC
9	+5V DC
10	Button 4
11	Joystick 2 - X
12	MIDI Transmit / Ground *
13	Joystick 2 - Y
14	Button 3
15	MIDI Receive / +5V DC *

Note that the port has input for 2 joysticks, a splitter lead is required to connect both.
* - Ports without MIDI have pins connected to 5V / Ground as shown.

VGA / SVGA Video (15-pin  High Density & 9-pin):

Pin	Function
	9-pin VGA	15-pin HD VGA	15-pin VESA DCC (PnP)
1	Red	Red	Red
2	Green / Mono	Green / Mono	Green / Mono
3	Blue	Blue	Blue
4	Horizontal Sync	ID Bit 2	Reserved
5	Vertical Sync	Ground	Ground
6	Red Ground	Red Ground	Red Ground
7	Green / Mono Ground	Green / Mono Ground	Green / Mono Ground
8	Blue Ground	Blue Ground	Blue Ground
9	Sync Ground	No Pin	+5V DC
10	-	Sync Ground	Sync Ground
11	-	ID Bit 0	ID Bit 0
12	-	ID Bit 1	DCC Serial Data
13	-	Horizontal or Comp. Sync	Horizontal or Comp. Sync
14	-	Vertical Sync	Vertical Sync
15	-	ID Bit 3	DCC Serial Clock

Note that the ID bits are inputs to the computer and are optional.
VESA DCC supports plug-and-play operation and is used by all modern monitors and video adapters. The serial clock and data lines are bi-directional.
All other signal lines are outputs.

Serial Mouse (9-pin):

Pin	Function
1	Data
5	Ground (0V)
8	+5V DC
9	Clock
All other pins unused

For PS/2 mouse connections see Mini DIN Connectors

AUI Thick Ethernet Port (15-pin):

Pin	Function
1	Control In Shield
2	Control In A
3	Data Out A
4	Data In Shield
5	Data In A
6	DC Power Common
9	Control In B
10	Data Out B
11	Data Out Shield
12	Data In B
13	DC Power +
14	Power Shield
All other pins unused

IBM Token Ring Network Adapter (9-pin):

Pin	Function
1	Ring In
2	Ground
3	+5V DC
4	Ground
5	Ring Out
6	Ring In
7	Ground
8	Ground
9	Ring Out
All other pins unused

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Connector Assembly Instructions

Chassis:

Chassis plugs and sockets normally have solder bucket terminations. Soldering can be difficult to the close spacing of the pins - heatshrink sleeving will help here. To make a cable-mounted connector a cover can be fitted to the connector. Note that a 9-way cover will be needed for a 15-way HD connector.

PCB Mounting:

Solder pin connections, normally the connector will have extra pins or lugs for support. Available in straight or right-angle versions, the latter being more common.

IDC Connection:

Used with ribbon cable to greatly simplify assembly. Insert cable into connector and squeeze shut with a vice, this will pierce the insulation and make the connections. Another advantage is that more than 2 connectors can be fitted to a cable. Covers are not needed on IDC connectors.

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