string(241) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E6%8B%89%E5%8D%A1%E6%8B%89pos%E6%9C%BA%E6%93%8D%E4%BD%9C%E6%B5%81%E7%A8%8B => Failed to connect to 14.18.117.71 port 38093: Connection refused"
拉卡拉pos机操作流程
