Description
When processing critical process values (for controlling pumps, for example) you must make sure that operations and value changes cannot be made simultaneously by multiple clients.

For example, if the picture window for entering setpoint values for a pump is open on one client, then it must be impossible to open that picture window on all other clients.

Instructions
 

No.	Procedure
1	Create binary tag Create a binary tag named "ReleaseOperation" in the WinCC Explorer. If you use the "Redundancy" options package, "Tag synchronization" must also be enabled. Fig. 01 In the "Limits/Reporting" tab you specify the value "1" as start value for the tags. Fig. 02
2	Configure picture In the Graphics Designer, configure a new picture with the "PumpWindow" picture window and a button to display the picture window. Fig. 03
3	Parameterize button Label the button with this text: "Open pump window". Fig. 04 Dynamize the operator-control enable of the "Button" button in the "Properties" tab ("Button > Miscellaneous > Operator-Control Enable") with the "ReleaseOperation" tag. Fig. 05 Configure a direct connection to the "Button" button in the "Events" tab ("Button > Mouse > Mouse Action"). Fig. 06 Fig. 07
4	Parameterize picture window In the Object Properties of the "PumpWindow" picture window, select the "Properties" tab and set the value "No" for "Display" ("Picture window > Miscellaneous > Display"). Specify the picture name of the pump picture in the same mask. Fig. 08
5	Create a new script As long as the "PumpWindow" picture window is displayed the "Button" button must not receive operator-control enable. For this, in the Object Properties of the "PumpWindow" picture window you select the "Events" tab and dynamize the display ("Picture Window > Property Topics > Miscellaneous > Display > Change"). Fig. 09 VB-Script.zip ( 282 bytes )
6	Close picture window There are several ways of closing the picture window: In the Object Properties of the "PumpWindow" picture window, select the "Properties" tab ("Picture window > Miscellaneous") and set the value "Yes" for the "Border", "Title", "Can Be Maximized" and "Can Be Closed" attributes. In the pump picture you configure a button that will be displayed in the "PumpWindow" picture window. Open the Object Properties dialog of the button, select the "Events" tab ("Button > Mouse > Mouse Action") and create the direct connection below. Fig. 10 Note: Instead of the direct connection, a VB script is also possible if multiple decision criteria are required for closing the picture window: "Parent.Visible = False"