关于污水处理厂中生化池中溶解氧的控制，程序使用的是一般的PID控制，PLC模块存放在PLC的CPU中，m文件中有OPC通讯。-About sewage treatment plant biochemical control of dissolved oxygen in the pool, the program uses the general PID control, PLC module is stored in the PLC CPU, m is the file has OPC comm