Nine things you should know about D-Sub connectors

Nine things you should know about D-Sub connectors

Serial communication was all the rage—at one point it was one of the most common means of connecting peripherals such as printers, scanners, mice, and joysticks to personal computers. The most commonly used connector type for serial communications is the D-subminiature (D-subminiature) connector, also known as the D-sub connector. Although D-sub connectors have been replaced in some applications, they are still in use today and are utilized in various ways.

Here are nine things you should know about D-Sub connectors:

1. The D-sub connector used to be one of the smallest connectors used in computer systems. The D-sub connector gets its name from its D-shaped metal connector housing that wraps around the outside of pins or jacks that are arranged in two or more parallel rows to carry strings row data.

2. The connector shell is divided into five different sizes, and each shell size can have two different pin configurations. Standard housing sizes have two rows of pins, while high-density housings have three rows of pins.

3. Since the D-sub connector utilizes individual pins to carry serial data, it is extremely easy to customize. DB9 is a standard configuration with the smallest housing size. There are 9 pins in the housing, and the size is 1.3cm (height) × 3.1cm (width). The HD78 with the largest housing size is the HD78, which has 78 pins in its housing and measures 1.5cm (height) x 6.7cm (width). You can click here to view all D-sub housing sizes and configurations.

4. Cables with D-sub connectors can be much longer than other cables. RS-232, the current general standard for serial data, does not specify any length restrictions, and when special equipment is used, RS-232 cable lengths can reach hundreds of meters or more. In contrast, USB is limited to 5 meters in length.

5. Serial communication is often slow, especially in the case of long-distance transmission. Loss of communication can cause the software on the computer to stop unexpectedly.

6. D-Sub connectors are bulky, especially when compared with new connectors. This makes it difficult to connect and disconnect such connectors in tight spaces. However, right-angle adapters allow for a 90-degree turn without damaging the connector, which facilitates the use of D-Sub connectors in tight spaces.

7. Since the pins in the D-Sub connector shell are exposed, it is easy to bend or break. The best way to avoid pin damage is to protect the pins with a D-sub plug or socket cover to prevent damage when unmated. In addition, male-to-female converters and female protectors help reduce connector stress caused by repeated mating.

8. D-sub connectors can be mated without thumbscrews, but such a friction fit cannot guarantee that they will always be mated in place. On the other hand, while thumbscrews allow for a stronger connection, they increase the time required for connector mating and unmating.

9. At present, there are still many devices with DB9 ports, and there are various optional technologies for conversion of traditional products with D-sub connectors. With converters between RS232/422/485 and USB, Ethernet, and other technologies, you can still use old-fashioned serial devices with a variety of modern computers.

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