敷设时环境温度不低于:固定敷设-30℃,非固定敷设-18℃最小弯曲半径：无铠装层应不小于电缆外径的8倍，带铠装层的电缆应不小于电缆外径的14倍在20℃时用直流500V电压试验稳定充电1min后绝缘电阻应不小于2500MΩ•Km各对绞屏蔽之间以及对绞屏蔽与总屏蔽之间应不断路电缆的线芯和线芯之间以及屏蔽。
绝缘材料：高密度聚乙烯或聚丙烯，按照全色谱标准标明绝缘线的颜色绝缘线对：把二根不同颜色的绝缘线按不同的节距扭绞成对，并采用规定的色谱组合以便识别线对。
缆芯结构：以25对为基本单位，超过25对的电缆按单位组合，每个单位用规定色谱的单位扎带绕扎，以便识别不同的单位。
供电系统电表远控抄表数据传输线，供水系统水表远程数据传输信号线等2、产品说明：◆内导体使用多支退火裸铜绞合◆聚氯乙烯绝缘◆多芯芯线绞合成缆◆外包铝箔屏蔽◆铜线编织屏蔽◆聚氯乙烯护套◆额定电压Uo/U为300/300V◆长期允许工作温度应不超过70℃RS-485电缆信号线特性阻抗120欧姆，导体为2。
ZR-BPGVFP2硅橡胶绝缘丁腈护套铜带绕包屏蔽耐高温变频电力电缆。
ZR-BPGVFPP2硅橡胶绝缘丁腈护套铜丝编织铜带绕包屏蔽耐高温变频电力电缆。
ZR-BPGVFP3硅橡胶绝缘丁腈护套铝聚酯复合膜绕包屏蔽耐高温变频电力电缆。
普通双绞屏蔽型电缆 STP-120Ω（for RS485 CAN） one pair 18 AWG ，灰色护套，电缆外径8.2mm左右。
适用于室内、管道及一般工业环境。
使用时，屏蔽层一端接地。
下面讨论三相电机的转矩特性，由于其电流波形近似为正弦波，现将细分驱动时的转矩与两相电机比较来看。
如增加细分的细分数，电流波形能近似正弦波，磁通的高次谐波的影响更明显。
两相电机细分时的转矩磁通是不含高次谐波的正弦波，如式前一篇中的T2=IΦsinδ所示。
下图是对其磁通含三次谐波时的细分两相电机与三相电机转矩进行比较。
三相电机的各相转矩与两相电机的曲线相同，用下图式1表示。
交链磁通能用基波与奇数次高次谐波之和表示（偶数次的高次谐波与线圈交链时会抵消，不会变成交链磁通），基波与三次谐波之和如下图所示。
可采用任何一种方式敷设，更适于岩石地区的敷设。
在一定条件下，也可用于传输2048kbit/s以上的数字信号。
适用于市内、近郊及局部地区架空或管道敷设线路中，也可直埋。
索道通信电缆执行标准：YD/THYAC_索道电缆--索道通信电缆用途：HYAC-索道电缆--索道通信电缆适用于索道的通信线路，也适用于接入公用网上网专用网线路。
耐高温控制电缆:我公司是专业生产电线电缆的厂家.主要产品有F46系列耐高温电缆,仪表电缆,计算机电缆,本安电缆,DCS电缆.屏蔽电缆系列电线电缆.KFF,AF,KFFP,DJFPVP,KFFRP KFF、KFFP、KFF22、XKFF、XKFFP、XKFFP22 .耐高温控制电缆（KFFKFFPKF。
3、绝缘线对：把二根不同颜色的绝缘线按不同的节距扭绞成对，并采用规定的色谱组合以便识别线对。
4、通信电缆缆芯结构：以1对为基本单位，超过25对的电缆按单位组合，每个单位用规定色谱的单位扎带绕扎，以便识别不同的单位。
充油电缆主要电气性能：1.充油电缆直流电阻:20℃,0.4≤1480.5 ≤95.00.6≤65.80.8≤36.62.充油电缆绝缘电气强度：导体之间1min1kv不击穿导体与屏蔽1min 3kv不击穿3.充油电缆绝缘电阻：每根芯线与其余线芯接地，HYAT电缆大于3000MΩ.k。
Railway cables are suitable for transmission under rated voltage ac 500V or dc 1000V and below. Product name, model, specification and scope: plastic insulation and polyurethane sheath railway cable PTYAH; PTYA; PZYA; PTYV; PTYY,; PTY22; PTY23; (PZY02; PZY03; PZY23 PZY22) 1/0.8mm (1/1.0mm) 2-48 core is suitable for railway communication, fire alarm, telegraph and other automatic devices with rated voltage ac 500V or dc 1000V or below. Poly (PVC insulation composite sheath steel tape armoured polyvinyl chloride sheathed PTYA23 PTYA22 PTY23 PTY22 PTYAH23 PZYA23 PZYA22 PZY23 PZY22 0.8 mm (1/1.0 mm) 4-61 core is fit for ac rated voltage 500 v or dc voltage 1000 v and below transfer audio and fixed laying railway and group control automation assembly line, can transport railway group general automatic letter, also can transmit the audio frequency shift automatic block and business calls. ? 4, using features: cable in - use under 40 ℃ to + 50 ℃. Cable conductor long-term working temperature shall not exceed 70 ℃. Ordinary sheath of the cable laying under the temperature below 5 ℃, resistance to sheath for - 10 ℃. The bending radius shall not be less than 15 times of the outer diameter of the cable (when laying) and shall be applicable to any horizontal difference
Tianjin cable pull branch factory in line with the principle of "customer is", with "honest, trustworthy, thoughtful" service concept won the trust of the extensive business.
Modbus是plc应用中常用的通讯手段，轮询是在进行一个控制器连接多个从站的通讯时常用的编程手段，由于ST语言在数据处理上的优势，此方法变得更为简单。
下面以西门子S71214CPLC的ModbusRTU通讯为例，展现ST语言下的modbus通讯和轮询。
硬件连接要准备的硬件和软件：1.西门子plc1214C；2.通讯板CB1241；3.USB转RS485转换器；4.Modscan2/Modsim32电脑模拟软件模拟主/从站，5.SPU(serialportUtility)，监视通讯报文。
Spin cassette XF5-273 communication cable transfer box, adopting advanced technology at home and abroad, in accordance with the international advanced standard production in the eighty s of cable wiring e, for the city, the town of telecommunication network backbone cable and wiring cable transfer. Features: 1. The connection jumper adopts rotary clamp-type connection and is sealed with silica gel on the metal clip, because it is not only reliable and durable, but also easy to operate and repair without stripping. 2. The wiring terminals in the handover box shall be arranged in 25 pairs as a basic unit, consistent with the basic units of the local telephone cables and marked with Numbers on the terminals to facilitate construction and maintenance. 3. The structure, arrangement and installation dimensions of the wiring modules are exactly the same as those of 3M products and can be used for each other. 4. The box body is treated by electrostatic spraying, beautiful and generous, with clear lines, good anti-corrosion and waterproof performance and long service life. Main technical parameters: the environment temperature: - 40 ℃ ~ + 65 ℃ atmospheric pressure: 70 ~ 106 kpa relative humidity: 95% or less is random ends and insulation resistance between terminals and ground > 5 x 104 Μ Ω. When connecting any two ends and any terminals and grounding to 1000V ac, there shall be no breakdown or flying arc in 1min. Contact resistance between wire and terminal < 5 x lO - 3 Ω.
DJYPV(R)P22聚乙烯绝缘铜丝编织分屏总屏聚氯乙烯护套钢带铠装计算机用屏蔽(软)电缆。
DJYV(R)P2-22聚乙烯绝缘铜带绕包总屏聚氯乙烯护套钢带铠装计算机用屏蔽(软)电缆。
DJYP2V(R)22聚乙烯绝缘铜带绕包分屏聚氯乙烯护套钢带铠装计算机用屏蔽(软)电缆。
最小弯曲半径:无铠装电缆应不小于电缆外径的6倍;有铠装电缆应不小于电缆外径的12倍℃。
三、BV电线BV线用途一般用途单芯硬导体无护套电缆，适用于交流电压450/750V及以下动力装置、日用电器、仪表及电信设备用的电缆电线。
Direct selling by the manufacturer; "HYA communication cable /25 logarithmic cable/three types of line/line/cable; 25 large logarithmic cable HYA(1000 to 1200 to 1400 pairs)X0.4 line diameter low smoke low halogen burning large logarithmic cable wdz-hya wdz-hya53; WDZ HYA23 flame retardant with large logarithmic wire type ZR - manufacuring HYA, ZR - HYAC, ZR - HYAT, ZR - HYA53, ZR - HYAT53, ZR - HYV, ZR - HYA23, ZR - HYAT23, ZR - HYA22, ZR - HYAT22 multi-cores cable is 1000 to 1200 to 1400 to 1600 to 1800 to 2000 to 2400 manufacuring HYA multi-cores cable line by 0.4 0.5 0.6 0.7 HYAT communication cable (HYAT600 * 0.4)