9-Pin D-Sub Connector, Size 20 Contacts, Insert Arrangements
9-pin Dsub Pin Locations, Standard density
9 Pin D-sub
This connector may be terminated using any of the following terminal styles; Crimp, Solder, Insulation displacement contact (IDC), or Printed wiring board (PWB).
This connector is defined by the DOD standard:
MIL-DTL-24308; [Connectors, Electric, Rectangular, Non-environmental, Miniature, Polarized Shell, Rack and Panel, General Specification] and a number of sub specifications which define the types of connectors and the connection styles.
A board mount D-sub connector may be either straight or right angle; however, the pin spacing remains the same regardless of the style. A cable terminating connector would be straight only.
D-Sub Connector Insert Arrangements [D-Subminiature sizes]
The 9 pin arrangement is the most commonly used Dsub style.
D-Sub Connector Dimensions [D-Subminiature Out-lines]
Military D-Sub Connector Manufacturers [MIL-C-24308 Vendors]
Use the graphic for the 9 pin Dsub to determine the location of pin 1.
The most common application of the 9-pin Dsub connector was as the COM port on personal computers [Communication port]. The common name for the 9-pin connector was DB9, although the correct term is DE9. The DB9 connector was used on personal computers from the early 1980's up until the mid 2000's when the COM port began to disappear from PCs. By the late 1990's the computer mouse began to use the circular DIN as an interface instead of the DB9 connector. However the port could still be used as an RS232 port, although most users would not have a need for an RS232 port. Anyway another 5 years later most PCs were no longer shipping with a COM port, meaning the DB-9 had been removed.
An industrial user could just add an expansion card to add the DB9 and RS232 to a personal computer.