D sub have many different types:
popularly they are standard D-sub, high density d-sub, waterproof d-sub, mix function d-sub.
From pins DB9, DB15, DB25,DB26,DB37,DB44,DB57, DB62 etc.
many industrial fields use D-sub, but consumer fields have been started to reduce use them.
D sub dadvange is
1:very reliable, strong, can work in some very bad situation and can work for many years still no problem, then when we use in machine or some instruments
or equipments it is a very good choice.
2:The length of cables using D-sub connectors can be much longer than other cables. The current general standard RS-232 for serial data does not specify any length limitation, and when using special equipment, the RS-232 cable length can reach hundreds of meters or more. In contrast, the length of USB is limited to 5 meters.
3:Currently, there are still many devices with DB9 ports, and there are also various optional technologies for conversion of traditional products with D-sub connectors. Through the converter between RS232/422/485 and USB, Ethernet and other technologies, so D-sub cable is still popular to work.
D sub disadvange is
1:very big, pull in and push out very slow. the weight and height is quite huge compare with USB, HDMI, Type c etc.
2: Serial communication is often slow, especially in the case of long-distance transmission. Communication interruption can cause the software on the computer to stop unexpectedly.
3: D-Sub connectors are bulky, especially when compared with new-style connectors. This makes it difficult for such connectors to be connected and disconnected in a narrow space. However, the right-angle adapter can achieve a 90-degree turn without damaging the connector, which helps the application of D-Sub connectors in small spaces.
4: Since the pins in the D-Sub connector housing are exposed, they are prone to bend or break. The best way to avoid pin damage is to protect the pins with D-sub plugs or socket protective covers to prevent them from being damaged when they are not mated. In addition, the male-to-female converter and female head protector help reduce the stress on the connector caused by repeated plugging and unplugging.
5: D-sub connectors can be mated without using thumb screws, but this type of friction fit cannot guarantee that they will always be mated in place. On the other hand, although thumb screws can achieve a firmer connection, they increase the time required for connector plugging and unplugging.
