Optical fiber pigtails are commonly used network connection products in optical fiber networks. The question of how to configure optical module pigtails has always been a question for many people. The following editor will talk about how to configure optical module pigtails. Of course, I will also share some fault cases about improper use of pigtails.
How to configure an optical module pigtail
Let's talk about the commonly used models of pigtails: LC-LC; LC-FC; LC-SC; FC-FC; FC-SC; SC-SC, etc. These are the more commonly used models. There are also pigtail lengths: 1, 2, 3, 5, 10, 15, 20, 30 meters, the most commonly used are 1, 3, 5, 10, 15 meters, the length is according to the equipment and ODF box distance is determined.
The number of pigtails depends on what optical modules are used. There are two single-core optical modules, and four if they are dual-core optical modules. The mainstream is still dual-core optical modules, and two core switches and two aggregation switches are added. There are 4 pieces. Intelligent engineering basically uses LC-LC pigtails, and LC-FC pigtails are also used. There are many flanges of this kind of fiber optic disk, which is easy to find in the market and convenient for later maintenance and replacement.
The configuration of BBU and RRU pigtails for communication 3G/4G is also the same. There are 2 BBUs and 2 RRUs each, which adds up to 4. Basically, they all use dual-fiber cores, and the pigtail type LC-FC used for communication equipment.
Finally, let’s talk about the pigtail, because the pigtail is basically used on the equipment, and it is very close to the equipment. 3m/5m/10m are used the most. When matching pigtails, it must be well matched. If the pigtails are too long, the pigtails are piled in the cabinet or ODF box, which is ugly. If they are too short, they cannot be routed along the lines. Flying fibers are also ugly, and the distance is just the best.
There is another possibility that pigtails may be used. The optical cable does not go directly from the start point to the end point. This is equivalent to an extra jump point. Normally, two fiber optic splitter boxes need to be fused, so fiber jumpers are needed here. , If the optical module is a two-fiber type, two jumpers are required in the middle of the two split lines, and they are connected to form a jump point. In this case, the commonly used jumper is FC-FC. of. Another problem with pigtails is that they are easily damaged, or the optical attenuation is too large, which will make them unusable. Therefore, when reporting pigtails, add about 1% more to ensure the loss of layer fibers.
Optical module pigtail
Sharing of fault cases of improper use of pigtails
Case number one
problem analysis:
In the newly opened community, the central office could not register, and the construction team was called to check. It was found that the LOS of the ONU was red, indicating that the signal was not enough, but the signal was sent from the computer room. The PON signal passed through the 2 splitter to the transfer box, and then passed From the eight splitter to the light spot, the two splitter generally attenuates 3.8db, the eight splitter generally attenuates 11db, and then there is a margin attenuation after subtracting the distance link and flange. To calculate, the flange is calculated according to a 0.2db, the signal should be about -21db, why the signal is not enough, and later called the construction team to take pictures to see, and found that the pigtails of the ONU are SC/APC, and we usually If you use SC/PC, there will be a signal difference of about 4db. The attenuation of SC/APC is relatively large, and the sensitivity of ONU is generally greater than -24db.
Solution:
Let the construction team re-use SC/PC welding.
Experience sharing:
When sending signals, it is necessary to know the attenuation value of each device and the range of the received signal of the device.
Case 2
problem analysis:
In the light spot test, the optical signal is normal and the level is normal, but the signal to noise ratio is not up Which part of the line has the problem. I can only check the optical box one by one. It is found that the SC/PC head is connected to the SC/APC connector. It is normal to replace the SC/PC with the SC/APC.
Solution:
Change the connector from SC/PC pigtail to SC/APC.
Experience sharing:
Generally, the PC head should be connected to the PC head, and the APC head should be connected to the APC head. If the APC is connected to the PC head, there will be end surface reflection, while the TV uses the APC head to reduce reflection loss.
The above is the whole content of how to configure optical module pigtails and the fault cases of improper use of pigtails. In fact, pigtails are simply a fiber optic cable with connectors at one end at both ends.
