Integrated wiring-crystal head

The crystal head is named "Crystal Head" because it looks like a crystal. It is an important interface device in network connection. It is a plastic connector that can be inserted in a fixed direction and automatically prevented from falling off. Ports, hubs, switches, telephones, POE power, and other network communications.

       The name RJ stands for Registered Jack and is a USOC (Universal Service Ordering Codes) code derived from Bell System. FCC68.5000, IEC60603-7, TIA-968-A, GB / T 17535 specify the detailed dimensions of the crystal head.

1.Classification of crystal head

       According to the hole position and contact point of the crystal head, it is commonly used in data and voice systems: 4P2C, 4P4C, 6P2C, 6P4C, 6P6C, 8P8C; where P (position) is the hole position of the crystal head, C ( Contact) is a gold-plated electrical contact point on the phosphor bronze surface.

1.1 RJ11 crystal head

       The RJ11 crystal head only has 4 pins, and there are two types of 4P4C and 4P2C. In computer systems, RJ11 is mainly used to connect modem modems.

1.2 RJ12 crystal head

        The RJ12 crystal head has 6 pins, which are classified into 6P6C, 6P4C, and 6P2C. In computer systems, RJ12 is mainly used for voice communication.

1.3 RJ45 crystal head

        The RJ45 crystal head has 8 pins (8P8C), which are unshielded and shielded. It is used for the termination of data cables to realize the connection and change of equipment and distribution frame modules. It is mainly used for data communication.

1.3.1 Line sequence of RJ45 network jumper:

        The RJ45 network jumper has two connection methods, T568A and T568B. Generally, the T568B connection method is used.

Due to the use of hand-pressed termination at the construction site, it is not possible to ensure that the contact points of each crystal head are uniformly stressed, so that it is not guaranteed whether each contact point is short-termed. It is recommended to terminate the network jumper at the construction site.

2, the choice of crystal head

        Among the network passive products, the crystal head can be said to be one of the smallest and cheapest devices; however, it plays an extremely important role in the network, and it must not be easy or greedy when buying. Small and cheap causing unnecessary trouble. In order to avoid buying inferior crystal heads, let's tell everyone how to buy crystal heads that go straight to that one.

2.1 Identification from the appearance

     A good crystal head looks bright and transparent, and the body is smooth and uniform in color. The plastic shrapnel on the back can be easily bent around 180 degrees without breaking, and there will be no obvious deformation and fractures when released.

2.2.Verify from size

       Check the shape of the crystal head, because the size of the crystal head is strictly regulated, we can verify the size of the crystal head.

2.2.1 Measurement verification

        If a measuring tool is available, we verify the main dimensions in accordance with GB / T 17535.

2.2.2 Cooperation verification

         If there is no measuring tool, you can connect the crimped crystal head to other devices (network cards, switches, etc.) that have RJ-45 ports. After the connection, if the left and right sides do not shake, and the plugging and unplugging are smooth, the size specifications are more accurate. ; On the contrary, there are obvious gaps after connection, and the insertion and removal are not smooth, indicating that the manufacturing process is not passable and there are quality problems.

2.3 Judging from the copper sheet

      The most important part of the crystal head is the copper piece at the contact end, and its quality directly affects the plug-in life and contact resistance performance of the crystal head.

When inspecting the copper sheet, first check whether the cut edges of the metal terminal part are neat. Because inferior products are not enough in the manufacturing process, there will be many metal burrs when viewed with a magnifying glass.

Judging from the color of the copper plate, the surface of the good crystal head copper plate is gold-plated, and the color should be golden yellow, and the color should be uniform, and there should be no exposed bottom (uneven gold plating). However, inferior products may be oxidized and darkened due to the requirements of the gold plating process.

3.Troubleshooting

1.The channel or link is disconnected

        Check whether all parts are connected well? Is the module or patch panel termination intact? Check the report after testing with Fluke, and follow the instructions in the report to make corrections.

2.The switch indicators 100M and 1000M are changing.

       One or more of the 8 wires of the channel are not connected well.

3.The jumper is not inserted smoothly

3.1 The size of the crystal head or the interface connected to the crystal head does not meet the standard requirements.

3.2 The size of the crystal head reed does not meet the requirements.