Siemens S7-300 用户手册

SIMATIC S7-300 Getting Started for First Time Users

Getting Started, 04/2007, 6ZB5310-0NC02-0BA0

You must establish an online connection between the PC and CPU 312C for the 
following:

• Downloading and testing the control programs

• Displaying and changing the operating state of the CPU 312C

• Displaying the module status

• Hardware diagnostics
To establish an online connection, you must connect the PC and CPU 312C to 
one another via the MPI interface.

STEP 7 Lite attempts to establish the online connection on startup.
If the connection exists, the operating state of the CPU 312C is displayed in the 
status bar as “STOP”.

If no connection exists, the status bar displays “Disconnected”.