Hello Sundar;
First, here is a link to Siemens'
PCS7 Portal, where you can find brochures, manuals and technical information on the PCS7 offering.
Now, for a very brief presentation: PCS7 (Process Control System) is Siemens' newest Distributed Control System (DCS)-type product. It is based on S7-400 PLCs (for control, based on Step 7), Industrial Ethernet and Profibus for communications, and WinCC for Monitoring and Controls.
However, all these different programs are inter-relatd. You do not program the PLCs independantly from the SCADA, as you would in regular applications.
You use 2 special programming packages in the PLCs:
CFC and
SFC; to put it simply, all control blocks are brogrammed in CFC (Continuous Function Chart) and then the seqwuence of calls of all the control blocks is organized in SFC (Sequence Function Charts). WinCC is the SCADA programming software for monitoring abnd control.
What is special about CFC librairies is that they include, directly in their code, attributes for monitoring (for the SCADA). For example, if, while designing the typical control chart of a motor in the PLC (on the ES [engineering station in PCS7, where Step 7 and supporting software is located] you use a block named ALARM_8P, then you can create up to 8 distinct alarm points that you can name and parametrize, directly in the PLC, for that control block. When you complile your program, the WinCC application (called OS [operator station] in PCS7) will create a standard page or faceplate for the control of the motor, with up to 8 separate icons for your programmed alarms that you can use directly in the graphic page; in Runtime, these alarm icons will be animated through the PLC control block.
Of course you do not limit yourself to this in the WinCC application; you still have to design the static graphic pages, write scripts, program dynamic wizards... But the main difference between "Standard" WinCC and PCS7 WinCC is in the inter-compilation of the CFC control blocks.
This was a very brief presentation, maybe not as clear as you could have wished. I suggest you use the links above to gather more information on the subject.
Hope this helps,
Daniel Chartier