Procedure for Deleting an Object
Deleting an object within LookoutDirect that is used in a connection and/or an expression can become difficult if not performed in the correct sequence. The basic criteria for deleting an object is that all connections and expressions using the object must be removed before it can be deleted. The dialog below is the error message that appears when attempting to delete an object that's still being used in a connection or expression.
The following is an example of deleting a switch using one of the example programs (quickstartsvga.lkp) that is included in the LookoutDirect installation.
Start LookoutDirect and open the QUICKSTARTSVGA.LKP process file and change to the PLCDirect Interfacing screen.
Ungroup the Output Y0 switch and indicator then select the switch graphic and press your delete key to delete it from the screen. This deletes the graphic representation only not the object.
Note: It is not necessary in this example to delete the Y0 indicator since its expression does not include the switch. Its expression is directly monitoring Y0.
Switch to Edit Mode (Ctrl-Space), if you haven't already, and from the menu bar select Object>>Edit Connections and click on the driver object D4_450 and click Ok
Now that the connections to SwitchOuputY0 have been removed the object can be successfully deleted.
From the menu bar select Object>>Delete and click on the switch object SwitchOuputY0 then click Ok.
Step 6 (Optional)
Occasionally you may have several connections and/or expression that use the same object you want to delete. Currently there is not a cross-reference feature that will show you where each of your objects are being used and this can cause confusion when trying delete an object. One way to identify all instances where an object is being used is to open the source file in a word processor program, such as MSWord, and search for all occurrences. Simply locate and open the source file (QUICKSTARTSVGA.LKS) into your word processor.
By using the Find and Replace feature in your word processor you can identify what expressions and connections are using the object you want to delete, and on which screen they reside.
Caution: Be very careful NOT to make any while the *.lks (source) file is open. Any changes may have adverse effects and/or corrupt your LookoutDirect project. When exiting this file do not save any changes.