According to the actual requirements of the data acquisition terminal of the automatic feeding mixer truck and considering the universality of the module, the technical indexes of the terminal are determined as follows.

（1）模块工作电压：本终端的工作电压来源于车载电瓶，通常为 12V 或者24V，模块电压应小于电源电压；

(1) Module working voltage: the working voltage of this terminal comes from the on-board battery, usually 12V or 24V, and the module voltage shall be less than the power supply voltage;

（2）通讯方式：可采用无线网络和短信息方式通讯；

(2) Communication mode: wireless network and short message communication can be adopted;

（3）终端在线率：为了确保终端与监控中心数据交流的实时性，终端应保持高在线率；

(3) Terminal online rate: in order to ensure the real-time data exchange between the terminal and the monitoring center, the terminal shall maintain a high online rate;

（4）丢包率：丢包率是指测试中，所丢失数据包数量占所发送数据包的比率，为了降低数据丢包率，在设计中可以考虑，发生无线传输模块不能连接网络，导致终端不能登录系统的情况时，待无线传输模块脱离盲区后，将数据补传服务器；

(4) Packet loss rate: the packet loss rate refers to the ratio of the number of lost packets to the transmitted packets during the test. In order to reduce the packet loss rate, it can be considered in the design that when the wireless transmission module cannot connect to the network, resulting in the terminal unable to log in to the system, the data will be transmitted to the server after the wireless transmission module leaves the blind area;

（5）定位精确度：车辆监控调度系统的电子地图精度数量级是米，我国二级道路的标准宽度为 30~60m，如果要对车辆进行准确的监控，定位精度需控制在30m 以内，否则，当两条道路的距离过近时，就可能出现定位错误，即正在某条公路上行驶的车辆被定为在道路外或其它道路上。

(5) Positioning accuracy: the order of magnitude of the electronic map accuracy of the vehicle monitoring and dispatching system is meters. The standard width of the secondary road in China is 30 ~ 60m. If you want to accurately monitor the vehicles, the positioning accuracy needs to be controlled within 30m. Otherwise, when the distance between the two roads is too close, positioning errors can occur, that is, the vehicles driving on a certain road are determined to be outside the road Or other roads.