42C2的含义：
Error 42C2 - L4_DLL_E_LOGDEV
The logical device is not defined in the registry.
· Communication driver not correctly installed.
· Registry entry destroyed or deleted.
· Check the setting of the logical device name with the program ‘Setting the PG/PC Interface’.
· Check the setting of the logical device name in the window ‘System Parameters-Device’.
建议首先检查profibus通道的系统参数中的逻辑设备名称