1. Other programs are using computer serial port or USB port. In this case, it is recommended to close other programs or devices occupying serial or USB ports, and then restart Siemens 200 software.
2. There are conflicting device drivers in the computer. When installing some device drivers, it may conflict with drivers of other devices, resulting in the problem that the debugger is occupied. In this case, it is recommended to uninstall the conflicting device driver and try to reinstall the latest driver for this device.
3. There is something wrong with Siemens 200 software itself. In this case, it is recommended to reinstall Siemens 200 software and ensure that the latest version is used.
4, PLC programmer hardware failure. If external PLC programmer hardware (such as SiemensS7-200 programmer) is used, it may be that the hardware fails, resulting in the debugger being occupied. In this case, it is suggested to replace the hardware of PLC programmer or contact relevant technical support personnel for help.