Scada

I Have Worked On Op25,op17 Of Siemens,panelview 1000,1200,1400
In All These Mmi We Can Draw Bit Map Images Show Their States Whether On Or Off .also Inputs Are Fed From Hmi And Outputs Are Requested From Hmi To Plcs
We Also Can Have Data Logging And Get Data For That Specific Data
Also We Can Use Exel Data Base To Keep Record Of Data If It More Than One Dayor Two.
Could Any Body Guide Me Difference Between Scada And Hmi In Brief Using Example.

Difference.....

Welp,

Big difference between HMI & SCADA.

The 2 cent version follows:

HMI <~~~~ Just what it says, "Human Machine Interface" which just allows a user to view, enter, 'control' operation(s) within the SCADA system.

SCADA <~~~ 'Supervisory Control And Data Aquisition", system which 'can' depending upon programming just monitor field devices, or can actually control them, like turning pumps on/off & open/close valves, etc.

The biggest difference is the "data aquisition" part in "Supervisory Control And Data Aquisition".

A HMI typically only has the logging capabilities that its RAM memory allows. When power is turned off, the log is lost.
With some HMI panels, you can get recipes and datalogs out of the panel by means of a floppy or a flash card. But it is a cludge.
Some panels can log to a server on ethernet, but then it is no longer an integrated solution.

The other important difference between HMI and SCADA is the scope of the application. A SCADA application can be much bigger than a HMI application.

edit: By "HMI" I assume that you mean operator panels like the ones you have worked with.