LabVIEW环境下基于PPI协议的轨道车辆均衡试验测控系统研制

轨道车辆均衡试验要求单独控制8台液压油缸升降带动工装抬升轨道车辆，抬升过程中采集和存储抬升高度及轮重数据并计算轮重减载率，抬升到指定高度时自动停止。根据试验需要研制了轨道车辆均衡试验测控系统，系统的上位机采用PC，下位机采用S7-200系列PLC，在LabVIEW环境下编写程序，调用VISA接口函数通过PPI协议建立PC与PLC通信，采集、处理位移和称重传感器数据，控制液压油缸动作，最终实现了轨道车辆均衡试验测控系统的测控功能。

Measurement and Control System of equalizing test for rolling stock based on PPI protocol in LabVIEW environment

Equalizing test for rolling stock requires 8 sets of hydraulic oil cylinder which are controlled independently to drive the lift structure, needs to collect and store lifting height and wheel load data, calculate reduction rate of wheel load, and automatically stop when the rolling stock is elevated to a certain height. In this paper , according to the test need, a set of Measurement and Control System was developed, the upper computer was PC, the lower machine was S7-200 PLC, in the LabVIEW programming environment, the VISA interface function was called to establish the communication with the PC and PLC by PPI protocol, the data of displacement sensor and weighing sensor were collected and processed to control the hydraulic oil cylinder. The implemented Measurement and Control System of equalizing test for rolling stock could meet the needs of measurement and control.