ABB 模拟信号转换器；CC-E I/I 4-20mA/0-20mA 24V DC

　　ABB 模拟信号转换器；CC-E I/I 4-20mA/0-20mA 24V DC

　　1、采样，以模拟信号高频率2倍以上的采样速率采样，以后就能真实地还原信号，如，模拟信号高频率为4KHZ（普通话音），用8KHZ的速率采样，得到8000份样本。即分成离散信号

　　1, sampling, sampling rate of 2 times more than the highest frequency of analog signal, then it can restore the signal in real time. For example, the highest frequency of analog signal is 4KHZ (Mandarin tone), and 8000 samples are sampled at the rate of 8KHZ. That is divided into discrete signals

　　2、量化，看你对每一份样本分几级量化，分级越多，以后还原就越好，越接近原模拟信号，但产生的数据就越多，如果你分两级，每一份样本可以用两位二进制数字表示，0和1，如果分16级，就要用0和1表示16个不同的状态，就要用4位一组的二进制数字，如果分128级，就需要用7位二进制数字

　　You see, 2 quantization, several levels of quantization, each sample classification more, after the reduction is better, more close to the original analog signal, but the data is more, if you are divided into two grades, each sample can be represented by two binary digits, 0 and 1, if 16 points, to use the 0 and 1 represent 16 different states, will use a group of 4 binary digits, if 128 points, you need to use a 7 bit binary number

　　3、编码，把这些二进制数字编码传走，接收端反过来做就完成了模拟信号数字传输过程了

　　3, coding, passing these binary digital codes, and the receiver has done the analog signal digital transmission in turn.