Siemens SIMATIC S7-1200 - Page 375

Extended instructions
9.2 String and character
S7-1200 Programmable controller
System Manual, V4.2, 09/2016, A5E02486680-AK
375
Example: Calling GetSymbolPath over mutiple block call levels
The following example shows the use of GetSymbolPath over several call levels:
● Organization block OB1 calls the FB_Level_1 block, which in turn calls the FB_Level_2
block.
● The FB_Level_2 block executes GetSymbolPath to read the path of the parameter at the
REQ2 interface.
● Since the REQ1 interface supplies REQ2, the instruction determines the path of the input
parameter of REQ1.
● The MyStarterBit tag is the REQ1 input parameter. The bit is located in the MySTRUCT
structure in the MyDatablock data block.
GetSymbolPath reads this information and outputs the path
("MyDataBlock".MySTRUCT.MyStarterBit) at the OUT parameter.