摘要
针对工程实例中长距离控制蠕动泵时现场电磁干扰和模拟信号的衰减等导致蠕动泵流量出现很大误差的问题,提出了用数字信号代替模拟信号的传输方案,即由中央控制室内上位计算机通过Host Link通信协议远距离控制现场PLC,再由现场PLC通过模拟量短距离控制蠕动泵的方案,提高了信号传输的抗干扰能力,实现了蠕动泵流量的精确控制.工程实例表明:采用上述方案代替原有的0~10V模拟控制方案,利用LabVIEW的VISA函数实现上位计算机与OMRON公司CP1H型PLC之间的Host Link通信,将上位计算机控制信号传至80m外蠕动泵工作现场,可将原流量控制精度从6.89%提高到1.07%.
Aimed at the problem of large flow error of peristaltic pump due to site electromagnetic interference and analog signal attenuation during long-distance control in actual engineering,a signal transmission option with digital signal instead of analog one is propose,where the site PLC will be remotely controlled by the host computer in central control room with Host Link communication protocol and then the peristaltic pump will be controlled by the site PLC via analog short-distance control,so that the anti-interference ability of signal transmission will be improved and the precise control of pump flowrate will be implemented.It is shown by a real engineering example that by using foregoing option of substitution for original one with analog signal of 0~10Vand the LabVIEW VISA functions to achieve Host Link communication between host computer and OMRON Corporation PLC CP1 H send the control signal from host computer to peristaltic pump work site of 80 mafar,the flowrate controlling precision can be improved from can original 6.89%to 1.07%.
出处
《兰州理工大学学报》
CAS
北大核心
2017年第3期50-53,共4页
Journal of Lanzhou University of Technology
基金
国家自然科学基金(51365028)
