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6/12/2010 8:21 PM | |
Joined: 12/22/2006 Last visit: 1/25/2022 Posts: 1742 Rating: (308) |
Hello, Without you are aware of it, the STEP7 editor uses AR2 in some situations (not visible by the user): - The DI-Register and the address register AR2 are used for FB and multi instance CALL and may not be changed within FBs - The command "L P#Parametername" loads the address offset of the specified parameter within a FB in relation to the address register AR2. See also: Why are indirect calls using AR2 replaced by static local variables after saving the block? http://support.automation.siemens.com/WW/view/en/22531225 And if you make any change to AR2 (in a FC for instance), you must save its value before using it and restore its value before leaving. See also: "Avoiding errors when calling modules" in the help to STEP 7. |
Last edited by: jklm at: 6/12/2010 8:23 PMBest regards |
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