老外这样制作跳线

A s with many types of cable,you can save some money bypurchasing Ethernet cable and connectors and assembling/termi- nating them yourself. Of course, keep in mind that put- ting together cables of any type requires time, patience and some know-how. Without these essential ingredients, you’ll be much better served by buying pre-terminated cables. That said, let’s get started. First, to attach any Ethernet RJ-45 connector ends to the lengths of cable, you’ll need an RJ-45 crimping tool like the one shown in Figure 1. Start with a good quality cable, and cut a piece to the appropriate length. For best result, choose a size that is at least three feet (about 1 meter) long, but not more than 325 feet (about 100 meters). A cable that is either too long or too short can cause transmission problems. Next, use wire strippers to remove about one inch of the cable jacket, taking care not to nick or cut the wires. If the wires are damaged even slightly, cut off the stripped section and start over – even minor abrasions can lead to crosstalk between the wires within the cable. Then separate the individual wires, arranging them in the order of the desired configuration, either straight- through or crossover. Be careful not to untwist the wires down into the jack- et; doing so will cause the cable to be out-of-spec and can also cause crosstalk. Select the right connector for your cable. They’re available for solid or stranded conductors, but are not inter- changeable. Flatten the wires into a line, the way they’ll be inserted into the con- nector, and cut them to a length of half of an inch with reference to the jacket. Make sure that all ends are even with each other. (And don’t strip the wires!) Next, insert the group of wires into the connector. By holding the RJ-45 connector with the clip facing down and the connector front facing away from you, pin 1 will be on your left. Be certain that each wire is insert- ed all the way so the tips of the wires at the front of the connector can be seen. The cable jacket should extend into the RJ-45 connector end by about a quarter of an inch, because there’s a secondary mechanism that will also clamp the jacket. Inspect the cable to verify that all wires are in the correct order and are Terminating Ethernet Cable A step-by-step tutorial Figure 1: A common RJ-45 crimp tool. (This one is a Greenlee available at Home Depot.) And be sure to line up everything carefully; it’s a one-shot connector. fully inserted into the connector. Then use the crimping tool to crimp the connector to the cable. The tool presses the connector in at the two points shown in Figure 2 Figure 2: If crimped properly, the connector clamps both the wires and jacket. Be careful not to untwist the wires down into the jacket to make a connection with the wires and to secure the cable jacket. Check the completed cable to ver- ify once again that the wires are in the proper order, that the connector is solidly attached to the cable, and that all wires are fully inserted up to the front of the connector. Use a cable tester that supports RJ-45 connectors to check your work. If the cable doesn’t work, you’ll need to cut off the connector and start over again, and you will not be able to re-use the connector. (It’s a “one shot” deal!) And voila! Your connector should be properly terminated, and you can move on to attaching the next one. May the bandwidth be with you…