WR-D4008  模拟输入模块  提供模拟量转485功能

WR-D4008 模拟输入模块是一款将远程现场的模拟量信号采集至计算机的设备。

模拟输入模块利用RS-485总线作为数据通信线路，提供模拟量转485功能，能够同时将模拟量输入至模块，并通过RS-485总线传输至计算机。由于采用RS-485接口作为通信接口，其能够多个模块组合传输更多路数模拟量信号，并且能够在485线路上分散配置，采用地址码进行区分，可以直接接入MODBUS RTU协议的组态软件。

模拟输出和数字输出的区别如下：

信号源工作原理不同：WR-D4008模拟信号处理的是连续信号，一般采用连续变化的电磁波或采用连续变化的信号电压来表示；数字信号处理的是离散信号，数字信号通常使用1和0表示。

输出方式不同：模拟信号一般通过传统的传输线路（例如：电话网、有线电视网）来传输；WR-D4008数字信号采用断续变化的电压或光脉冲来表示，一般则需要用双绞线、光纤介质等将通信双方连接起来，才能将信号从一个节点传到另一个节点。

失真情况不同：WR-D4008模拟输出直接转换成声音波形信号，一般的音频放大设备都能接收，但传输过程中会因各种原因产生失真；而数字输出则是以符合某种协议的数字串描述波形，因此在以后的传输过程中不会产生失真，但必须用有相应功能的设备接收。

WR-D4008 Analog input module is a device that collects analog signals from remote field to computer.

The analog input module uses the RS-485 bus as a data communication line to provide analog to 485 function, which can simultaneously input the analog to the module and transmit it to the computer through the RS-485 bus. As the RS-485 interface is used as the communication interface, it can combine multiple modules to transmit more analog signals, and can be distributed on the 485 line, using the address code to distinguish, and can directly access the configuration software of MODBUS RTU protocol.

The differences between analog and digital outputs are as follows:

The working principle of the signal source is different: WR-D4008 analog signal processing is a continuous signal, generally using continuously changing electromagnetic waves or using continuously changing signal voltage to represent; Digital signals deal with discrete signals, and digital signals are usually represented by 1s and 0s.

The output mode is different: analog signals are generally transmitted through traditional transmission lines (such as telephone networks, cable television networks); WR-D4008 digital signal using intermittent changes in voltage or light pulse to represent, generally need to use twisted pair, optical fiber media, etc. to connect the two sides of the communication, in order to transmit the signal from one node to another node.

The distortion situation is different: the WR-D4008 analog output is directly converted into a sound waveform signal, and the general audio amplification equipment can receive it, but the transmission process will cause distortion for various reasons; The digital output is a digital string that conforms to a certain protocol to describe the waveform, so there will be no distortion in the future transmission process, but it must be received by a device with the corresponding function.