If not, assign an initial value to the variable (column E). 3. It is suggested to add the following columns in the above table: (1) Add a column ":"after the variable column; (2) Add a column ":=" after the data type column; (3) Add a column ";" Finally. Note: Each instruction must be marked with ";" Character ends, otherwise there will be compilation errors in the future. 4. Save as a file with formatted text. At this point, the file type is ". prn”。 Click Save to confirm. 5. Rename the saved file to a file ". Awl "type. 6. Open step7, select the sources folder in SIMIATIC Manager and select Insert External Source in the menu bar. Select the created AWL file in the save path. Click "Open" 7. Double-click the imported STL source, open the file, and select Insert Block Template Database in the menu bar. 8. Delete the redundant additional description (green text), and cut and paste the variable table between "STRUCT" and "END_STRUCT". Set an appropriate DB block ("DATA_BLOCK DBXX"), and delete the variable "b0" and the instruction "b0:=6# 16#0 1" in "BEGIN" and "END_DATE_BLOCK" to form the form shown in the above figure.