Warning: array_combine(): Both parameters should have at least 1 element in /www/wwwroot/z.haodianxin.cn/z.php on line 322
Warning: Invalid argument supplied for foreach() in /www/wwwroot/z.haodianxin.cn/z.php on line 323
西门子PLC+变频器控制小车的题目，请帮我解答一下，步骤、说明尽量详细，感谢