1, code DJ - (series code) electronic computer shielded cable Y - (insulation code) high-pressure polyethylene F - (insulation code) fluoroplastic V - (sheath code) polyvinyl chloride (R - said many strands of soft wire core P - (block code) copper mesh shielding P1 tin plated copper mesh shielding P2 copper tape screened P3 aluminum-plastic composite membrane shielding for example 1:2, product specifications order 7 (14) to 1.0 was computer shielded cable can be represented as: (1) total shielding DJYVP7 * 2 * 1.0mm2 (2) partial shielding multiple soft lines DJYPVR7 * 2 * 1.0mm2 (3) total shielding DJYPVP7 * 2 * 2 * 1
Armored communication cable structure: 1. Basic cable: any filled and unfilled cable with single sheath or double sheath structure. 2. Armored communication cable mechanical protection layer: type 53 adopts 0.15mm thick corrugated steel belt, which is longitudinal wrapped on the basic cable and overlapped on both sides. The surface of the steel belt is coated with plastic to prevent corrosion and water intrusion. The type 23,22 has similar performance with double steel band wrapping. 3. Armored communication cable sheath: black high-molecular weight low-density polyethylene or polyvinyl chloride thin sheath. Sheath thickness may depend on the basic cable outer diameter. 4, identification and marking: cable appearance with permanent identification mark, tag, at no more than alternate 1 m intervals between 5, sheathed communication cable tag contents are: the diameter of wire, wire on the , type of cable, length, factory name and year of manufacture. 6. Armored communication cable electrical characteristics: the cable meets all the electrical re of the basic cable. 7. Cable length: mechanically protected cable is manufactured according to the standard length of the corresponding basic cable
铁路信号电缆使用特性：（1）电缆的使用环境温度为-40℃~+60℃（2）电缆导体长期工作温度应不超过+70℃。
（3）电缆敷设环境温度：聚氯乙烯外护套电缆应不低于0℃;聚乙烯外护套电缆应不低于-20℃。
（4）电缆的允许弯曲半径：非铠装电缆应不小于电缆外径的10倍；铠装电缆应不小于电缆外径的15倍。
2、电缆的使用特性及运行敷设条件额定电压0.6/1KV聚氯乙烯绝缘电力电缆①电缆导体的长期允许工作温度：≤70℃②短路时（最长持续时间不超过5S）电缆的最高工作温度：160℃③电缆敷设后经受直流电压3.5KV/15min不击穿。
100对及以上的电缆加有1%的预备对。
缆芯包带：用聚脂薄膜带绕包。
屏蔽：用轧纹或不轧纹金属带纵包子缆芯包带之外，两边搭接。
屏蔽带表面涂敷的塑料薄膜与护层粘接护套：黑色低密度聚乙烯。
吊綫：吊线为7股镀锌钢绞线，标称外径为6．3mm和4．75mm两种，其抗张强度分别不小于3000kg和1800kg，吊线用热塑性涂料涂敷，以防钢丝锈蚀。
plc编程中常说的双线圈双重输出是什么呢，我们简单具体说明下，看下图：双线圈动作梯形图双线圈就是输出在多个位置被使用就像上图的Y1，那么双线群造成的结果是怎么样的，我们用软件对上图进行一个模拟监控，三种情况，M1=ON、M3=OFF，M1=ON、M3=ON，M1=OFM3=ON。
1，M1=ON、M3=OFF情况1修改M1值为ON状态，M3值为OFF状态，发现Y1=OFF。
2，M1=ON、M3=ON情况2修改M1值为ON状态，M3值也为ON状态，发现Y1=ON。
一、产品简介本产品适用于额定电压1000V及以下对于防干扰性要求较高的电子计算机和自动化连接用电缆。
电缆地线芯绝缘采用具有抗氧化性能的K型B类低密度聚乙烯。
聚乙烯的绝缘电阻高，耐电压好，介电系数小和介质损耗温度和变频率的影响也小，不但能满足传输性能的要求，能确保电缆的使用寿命。
450/750 v polyvinyl chloride insulated control cable, applicable to dc and ac 50 hz, rated voltage 450/750 v power plants, power plants, factories, mines, ports and petrochemical enterprises such as long-distance control loop, as a connecting line between electrical instrumentation and automation instrumentation, phoresy all kinds of electric energy role, make the whole electric, reliable operation.
使用条件1、额定电压U0/U：0.6/1KV.2、电缆导体长期允许最高温度为90度,短路时最高温度250度3、安装敷设环境温度不低于0度,固定敷设时环境温度不低于-10度.4、电缆允许最小弯曲半径不小于15D(D-电缆外径,mm)产品性能1、设计采用符合GB/T规定的第5类软绞合铜导体。
Purpose of HYAT solid insulated filled cable: solid insulated filled cable is suitable for the urban telecommunication line of the local telecommunication network in the town of wuyu, and also for the special network line connecting to the public network. Mainly used for pipeline laying. The inner and outer surfaces of the cable core and the shield layer are filled with oil paste and poured to prevent water intrusion. The mechanical and electrical properties of the cable remain unchanged under conditions of 30~C - 60~C.
MT《煤矿用阻燃电缆阻燃性的试验方法和判定规则》及Q/TX001.3-2006《煤矿用塑料交联绝缘控制电缆》本产品适用于额定电压交流500V或直流1000V及以下传输铁路信号、音频信号或自动信号装置的控制电路，其中综合护套、铝护套铁路信号电缆具有一定的屏蔽性能，适宜于电气化区段或其它有强电干扰的地区。
Frequency converter cable symmetry design a: special cable for 1.8/3 kv and below frequency conversion motor, and symmetric 3 + 1 core and 4 core cable can only be used for the main power input cable, cable but good using symmetric structure. Inverter and variable frequency motor and cable must adopt symmetrical cable structure, symmetrical cable structure with three core and 3 + 3 core two kinds, 3 + 3 core cable structure is a small four to three core insulation wire core in the fourth core (neutral) is decomposed into three smaller insulation wire core section, the three big three symmetrical string cable core cable, special cable for 6/10 kv frequency conversion motor, the cable structure and 6/10 kv power cable, ordinary ordinary power cable is three insulation wire core adopts copper tape screened after cabling.
“门口开灯，床头关灯”又称"一灯双控接法"，就是一个灯用两个开关都能控制灯的亮与灭。
常见的用处有，楼下开灯，上楼后楼上关灯；门口开灯，床头关灯；前门开灯，后门关灯等等，都是为了方便实现一个地方能开关灯，另一地方也能开关灯。
基本原理图如下它的原理非常简单，只需比单控开关多一条线就可实现，主要由两个双控开关来组合实现。
都是二选一开关，任何时刻，拨动任一开关，灯不是亮就是灭。
当左边开关拨动是灯亮的时候，右边开关拨动必然是灯灭，亦然。
MHYVRP煤矿用聚乙烯绝缘编织屏蔽聚氯乙烯护套通信软电缆。
MHY32煤矿用聚乙烯绝缘钢丝铠装聚氯乙烯护套通信电缆。
MHVV（HUVV）矿用聚氯乙烯绝缘阻燃聚氯乙烯护套电缆用于平巷、斜巷及机电硐室。
产品具有较强的电磁干扰、抗雷击及均衡电位、改善供电品质的特性，特别适宜计算机中心、航空航天监控中心、智能大楼等精密电子装置的场所。
■执行标准企业标准■使用特性1、导体的直流电阻参照聚氯乙烯绝缘及护套电力电缆2、交流电压试验成品电缆经受交流50HZ、5min、3500V的试验电压不击穿，对于单芯电缆，应进行浸水耐压试验。
阻燃电缆发展电线电缆行业是中国仅次于汽车行业的第二大行业，产品品种满足率和****占有率均超过90%。
在世界范围内，中国电线电缆总产值已超过美国，成为世界上第一大电线电缆生产国。
伴随着中国电线电缆行业高速发展，新增企业数量不断上升，行业整体技术水平得到大幅提高。
RS485 bus due to its wiring is simple, stable and reliable and widely used in video surveillance, access control intercom, building alarm and other fields, however, because there are a lot of in the process of 485 bus wiring is not completely accurate concept leads to many problems. Some wrong ideas will now be clarified.