Determining whether the decoder is good or not 1. Whether the protocol is applicable widely; 2. Whether the driving ability is strong; 3. Anti-interference ability and stability; 4. Lightning protection capability; 5. Whether the installation is convenient. The above points are described in detail: 1 : There are hundreds of 485 bus communication protocols for decoders, but mainly Pyleco D, Pyleco P, Samsung, and common DVRs.
Determining the quality of the decoder
1. Whether the application of the agreement is extensive;
2. Whether the driving ability is strong;
3. Anti-interference ability and stability;
4. Lightning protection capability;
5. Whether the installation is convenient.
The above points are described in detail:
1: There are hundreds of 485 bus communication protocols for decoders, but mainly Pelco D, Pyleco P, Samsung, and common DVRs all support the above protocols. The matrix usually uses Man code, because everyone is Pyleco. There are various theories in the analysis of the agreement, and various versions of the Pelco agreement are issued according to their own theories. The Pelco D version is the most, and I know about seven. The Manchester code protocol is usually applied in a matrix, and is mainly composed of AD and AB. With the small matrix gradually withdrawing from the market, the frequency of use of the code is also declining.
The decoder can automatically identify six protocols (including various versions of the Pelco protocol and the Manchester code protocol) without the need for jumper settings.
2: The driving capability mainly refers to the output of the decoder, including the PTZ control and the lens control. The PTZ control is basically a relay output because it is a 24V AC output. There are two design ideas for the lens control part, one is triode + resistance + optocoupler, this method is a low-cost design, the driving ability is slightly worse, it is more difficult for high-power or original three-variable lens drive, triode Easy to burn. The other way is that the lens drive is all relay output, the price is high, but the quality is stable. The output parts of Shenyang XK-JM series decoders all adopt the Guangzhou-Hong Kong relay. The quality is stable and the driving ability is very strong. It can drive 16-30mm electric lens.
3: Anti-interference ability is mainly reflected in the storage capacity of the CPU. When the data is lost due to external strong current, strong electric field or magnetic field, the decoder will not work normally. The CPU usually uses the 8051 series. The Shenyang First Kelly XK-JM series CPU uses the American original STC89C52 series. In the 89C52 and 8051 test examples on the Internet, when the 89C52 and 8051 are running at the same time, use the high-voltage spark igniter in the lighter (can issue an instant high voltage) to shock the 89C52 and 8051 pins, of which 8051 will crash every time the electric shock, 65% probability All data is lost. When the 89C52 electric shock hits 33% chance of crash, the data is not lost.
Another criterion for stability is whether it crashes. Usually, the decoder has a certain probability of crash. The solution of the decoder is to design a hardware watchdog circuit on the decoder to monitor the decoder operation. When a crash occurs. The decoder is automatically restarted. This method is more practical and is more common in industrial circuits.
4: Lightning strike is a common problem in the decoder. I often see the decoder being repaired by lightning and repaired by the lightning striker. The lightning strike decoder is not necessary for repair due to the large number of boards and components being burned. Lightning strikes are usually divided into two types, direct lightning and inductive lightning. Direct lightning refers to the direct action of the lightning on the object, causing damage to the object. Direct lightning will generally destroy the object.
Inductive lightning means that when a lightning strike occurs, a strong electric field is generated. A relatively close conductor generates an induced current. Usually, the induced current is relatively strong, but it is much smaller than a direct lightning strike.
When the decoder is struck by lightning more than 95%, the 485 bus generates inductive lightning, and the decoder, code conversion, computer, etc. are destroyed by the 485 bus. The design of Shenyang XK-JM series decoders through the lightning protection tower can effectively prevent the damage of the induced lightning below 10 millimeters. It has an effective anti-destructive effect on common inductive lightning.
5: Installation and use convenience is mainly from the perspective of humanization. The decoder adopts a pull-down rainproof design shell with a waterproof head and a two-way fuse, which fully meets the outdoor use conditions.
The terminal blocks of the circuit board are up-tilt design, the wiring is more convenient, the circuit board terminals are marked in Chinese and English, which is convenient for installation. The construction personnel can easily wire even if there is no manual.
The hydraulic system of medium and small hydraulic Excavator Spare Parts has a clear trend of changing to a variable system. Because the variable system compensates by increasing the flow rate when the pressure is reduced during the operation of the oil pump, the hydraulic pump power is kept constant, that is, the Excavator spare parts equipped with the variable pump can often fully utilize the maximum power of the oil pump. When the external resistance increases, the flow rate is reduced (the speed is reduced), and the digging force is multiplied; a three-circuit hydraulic system is used. Generate three independent work movements that do not affect each other. Achieve power matching with the slewing mechanism. The third pump is switched on in other working motions and becomes the second independent fast motion of the open circuit. In addition, hydraulic technology is commonly used on excavators, creating conditions for the application and promotion of excavators for electronic technology and automatic control technology.
Jining ChangSong Construction Machinery Co.,Ltd is founded in 2000,located in jining city,Shandong province.Which is the hometown of Confucious and Mencious,the Pearl of Canal.Based on the Supply Chain of Shantui.Komatsu Construction Machinery Manufacturer,we have advanced production equipment and Technical Staffs.Meanwhile,Welcome your OEM and ODM production requirement. From the year of 2009.We successfully won the supplier qualification of China Petroleum Pipeline Bureau(CPP),Sinohydro Corporation Ltd,China Railway Group Ltd.(CTCE).Shantui Imp&Exp Co.,Ltd ,China Datang Corporation etc Super Large multinational enterprises. Business Scope as follows:Shantui,Shanghai,Pengpu,Hebei,XuanGong,Inner Mongolia Dadi,Zoomlion series Bulldozer,Daifeng Pipelayer Maintenance Service and spare parts.
Excavator Spare Parts
Excavator Spare Parts,Excavator Engine Parts,Excavator Hydraulic Parts,Excavator Undercarriage Parts
Jining Changsong Construction Machinery Co., Ltd. , https://www.jncsmachinery.com