CompTIA A+® Certification All-In-One For Dummies®, 2nd Edition

1.6. Viewing Cable Adapters

Many types of adapters can join different types of cables and devices. The following sections give a brief description of some of the major types.

1.6.1. Barrel connectors

The term barrel connectors comes from Thinnet networking, where cables could be extended by means of an adapter, resembling a small barrel, that accepted a male connector on either end. This term is now often applied to any connector that extends the length of a cable by joining two cables but that does not change the pin configuration. Figure 1-14 shows a barrel or cable connector for an RJ-45 cable.

Figure 1.14. Use barrel connectors to extend the length of cables.

1.6.2. Gender changers

Gender changers are a bit of a strange beast. They are straight-through connectors that don't change the order or connection of the pins; they only change the sex of the connector that they are attached to. They look like a connector that has either two male or two female ends (as shown Figure 1-15); when attached to a cable of one sex, the connector becomes the other. These are used only in rare cases where your cables have the wrong sex connector, which is a situation that I often encounter with video connectors when working with KVM (Keyboard, Video, and Mouse) switches and cables made by different manufacturers.

Figure 1.15. Gender changers change the sex of a connector.

1.6.3. Null modem ...