Bus LengthAs the length of the bus

Bus Length
As the length of the bus increases, several factors degrade the differential signal transmitted.
The resistance of the copper wire reduces the signal level, although this is typically not
significant. 3 More significant is the attenuation of high-frequency components of the signal. This
can produce rounded edges on signal pulses, and can lead to inter-symbol interference (ISI) and
bit timing jitter. Because of these effects, the combination of bus length and signaling rate must
be considered. For most energy meter applications, signaling rates below 250 kbps are
adequate. The standard DL/T 645 specifies signaling rates below 100 kbps. At these rates, the
effect of high-frequency signal attenuation is negligible for bus lengths of even 1200 meters.
Transceivers such as the SN65HVD12 and the SN65HVD3082E have driver outputs optimized
for these signaling rates, and thereby have reduced levels of electromagnetic interference (EMI)
and reduced problems due to stub reflections on the bus.

結果 (中文) 1:

总线长度随着总线长度的增加，有几个因素会降低差分信号传输。铜线的阻力减小信号电平，尽管这通常是不重大。3 更重要的是对信号的高频分量的衰减。这可以产生信号脉冲，圆的边，可以导致符号间干扰 (ISI) 和位定时抖动。由于这些效应，总线长度与信号速率的结合必须考虑。对于大多数能量计应用信号低于 250 kbps 房价得到足够。标准的 DL/T 645 指定信号量低于 100 kbps。在这些费率高频信号衰减的影响是可以忽略不计的甚至 1200 米的总线长度为。如 SN65HVD12 和 SN65HVD3082E 收发器有优化的驱动程序输出这些信号的价格，并从而减少电磁干扰 (EMI)和公交车上的存根 （stub） 反射减少的问题。

結果 (中文) 3:

总线的长度随着总线长度的增加，几个因素降低了传输的差分信号。铜线的电阻降低了信号电平，虽然这通常不是显著。3更重要的是信号的高频分量的衰减。这可以对脉冲信号产生圆形的边缘，并可能导致符号间干扰（ISI）和位定时抖动。由于这些影响，总线长度和信号速率的组合必须被认为是。最能表应用，信令速率低于250 kbps充足的。标准DL/T 645指定信号率低于100 kbps。在这些费率中高频信号衰减的影响是可以忽略不计的总线长度甚至1200米。如sn65hvd12收发器和sn65hvd3082e有驱动器输出优化对于这些信号速率，从而降低了电磁干扰（电磁干扰）的水平由于在总线上的存根反射而减少的问题。