Contents Page

Absolute and Symbolic Addressing …........................................................................................... 2Symbolic Addressing - Overview …............................................................................................... 3Opening the Symbol Table ................................................................................................................ 4Edit: Find and Replace ……............................................................................................................. 5View: Filter ….................................................................................................................................... 6View: Sort ……................................................................................................................................ 7S b l T bl E t 8Symbol Table: Export ...................................................................................................................... 8Symbol Table: Import ....................................................................................................................... 9Edit Symbols (in the LAD/STL/FBD Editor) ……............................................................................... 10Symbol Information (in the LAD/STL/FBD Editor) ............................................................................. 11Symbol Selection (in the LAD/STL/FBD Editor) ............................................................................... 12“Leading Symbol" ......................................................................................................................... 13Exercise: Creating a Symbol Table for FC 15 .................................................................................. 14

Training Centerfor Automation and Drives

ST-7PRO1SymbolsPage 1

Absolute In absolute addressing, you specify the address (e.g. input I 1.0) direct. In thisAdd i d ‘t d b l t bl b t th i h d t dAddressing case you don‘t need a symbol table, but the program is harder to read.

Symbolic In symbolic addressing, you use symbols (e.g. MOTOR_ON) instead of the Addressing absolute addresses.

You store the symbols for inputs, outputs, timers, counters, bit memories and blocks in the symbol table.

Note When you enter symbol names, you don‘t have to include quotation marks. The Program Editor adds these for you.g y

Training Centerfor Automation and Drives

ST-7PRO1SymbolsPage 2

Global Symbols Global symbols declared in the symbol table can be used in all blocks of a program.The name in the symbol table must be unique, that is, a symbolic name must only appear once in the table.

Local Symbols Local symbols are declared in the declaration part of a block. They can only be used within that block.The same symbolic name can be used again in the declaration part of another block.

Training Centerfor Automation and Drives

ST-7PRO1SymbolsPage 3

Symbol Table You open the symbol table by selecting the menu options Options -> Symbol Tablei th LAD/STL/FBD Editin the LAD/STL/FBD Editor.You can also open the symbol table from the SIMATIC Manager: Select the program in the left-hand pane of the project window and double-click the “Symbols” object.

Table Structure When you open a symbol table, an additional window is opened. It consists of columns for the symbol name, the address, the data type and a comment for a symbol. Each symbol occupies one line of the table. A blank line is automatically added at the end of the table for defining a new symbol. g y

Note The symbol table is a common database and can be used by different tools:• LAD/STL/FBD Editor• Monitoring and Modifying Variables• Display Reference Data

Training Centerfor Automation and Drives

ST-7PRO1SymbolsPage 4

Find and Replace A number of options are available for finding and replacing text in the current window:• Find what:

Enter the text you are looking for.• Replace with:

Enter the replacement text. • From cursor down:

Searches downwards to the last line in the symbol table.• From cursor up:

Searches upwards to the first line in the symbol table.• Match case:

Only searches for the specified text with identical use of upper-case and lower-case letters.

• Find whole words only:Searches for the specified text as a separate word, not as part of a longer word.

• All:Searches through the whole symbol table, starting from the cursor position.S l ti• Selection:Searches only the selected symbol lines.

Note When you are looking for addresses, you should insert a wildcard after the address identifier, otherwise the address cannot be found.

Example of Find and Replace (replace all outputs with address 8. with address 4.):

Find what: Replace with:Q*8 * Q 4

Training Centerfor Automation and Drives

ST-7PRO1SymbolsPage 5

Q*8.* Q 4.

Filter Only the symbols which meet the active filter criteria (“symbol properties") are di l d i th t i ddisplayed in the current window. You can apply several criteria at once. The specified filter criteria are linked with one another.

Symbol You can select various filters and link them according to the following properties:Properties Name, Address, Data type, Comment, Operator control and monitoring,

Communication, Message.

Permissible wildcards are * and ?.

Examples Name: M*Only the names that begin with "M“, and that contain any number of additional characters, are displayed in the symbol table.

Name: SENSOR_?Only the names that begin with "SENSOR_" and that contain one other character, are displayed in the symbol table.

Address: E*.*Only the inputs are displayed.

Valid, Invalid The symbols must be unique, that is, a symbol or an address must only exist once in the symbol table.If a symbol or an address appears more than once, the lines in which it appears are displayed in “Bold". If your symbol table is long, and you want to find such ambiguous symbols or addresses more quickly, you can display only these lines of

Training Centerfor Automation and Drives

ST-7PRO1SymbolsPage 6

g y q y y p y ythe symbol table by selecting the menu options View -> Filter and the attribute “Invalid".

Sort The entries in the symbol table can be displayed in alphabetical order. You use the ti Vi > S t t if th l t b d th i t fmenu options View -> Sort to specify the column to be used as the point of

reference for sorting in the current window.There is an alternative way to sort:1. Click on the column heading for sorting in ascending order in this column.2. Click on the column heading once more for sorting in descending order in

this column.

Training Centerfor Automation and Drives

ST-7PRO1SymbolsPage 7

General The menu option Symbol Table -> Export enables you to store symbol tables in a diff t fil f t th t k th ith th Ydifferent file format so that you can work on them with other programs. You can select the following file formats:• ASCII Format (*.ASC)

- Notepad- Word

• Data Interchange Format (*.DIF)- EXCEL

• System Data Format (* SDF)System Data Format ( .SDF)- ACCESS

• Assignment List (*.SEQ)- STEP 5 assignment list

Training Centerfor Automation and Drives

ST-7PRO1SymbolsPage 8

General The menu option Symbol Table -> Import enables you to import symbol tables that t d ith thwere created with other user programs.

What to do:1. Activate the menu options Symbol Table -> Import.2. Select the file format in the “Import” dialog window.

You will find the same formats as for Export.3. Select the directory path in the “Find in:" list box.4. Enter the file name in the “File Name:" box5 Confirm with "OK"5. Confirm with OK .

File Types You can import the following file formats:• ASCII Format (*.ASC)

- Notepad- Word

• Data Interchange Format (*.DIF)- EXCEL

• System Data Format (*.SDF)- ACCESS

• Assignment List (*.SEQ)- STEP 5 assignment list

Training Centerfor Automation and Drives

ST-7PRO1SymbolsPage 9

Edit Symbols The menu option Edit -> Symbol, or a click with the right mouse button on the dd d th th ti Edit S b l bl t i b liaddress and then the menu option Edit Symbol, enables you to assign symbolic

names to absolute addresses later on. The assigned names are automatically entered in the symbol table. Names that are already in the symbol table are displayed in a different color. They cannot be used again in the symbol table.

Training Centerfor Automation and Drives

ST-7PRO1SymbolsPage 10

Addressing In the LAD/STL/FBD Editor you can choose to display the addresses in one of the f ll i t b l ti th ti Vi > Di l > S b lifollowing two ways by selecting the menu options View -> Display -> Symbolic Representation:

• Symbolic Addressing or• Absolute Addressing .

You can display the symbolic and absolute address assignments used in the network by selecting the menu options View -> Display -> Symbol Information.The assignments are found under the network in LAD/FBD and in STL they are found in the statement line.

Note If you position the mouse pointer on an address, a "Tooltip" appears with the symbol information for this address.

Training Centerfor Automation and Drives

ST-7PRO1SymbolsPage 11

Introduction You can use the menu options View -> Display -> Symbol Selection to simplify the iti f b liwriting of a symbolic program.

When you label the adddress, a section of the symbol table pops up, as soon as you enter the first letter of a symbol name. This section contains all symbols which begin with this letter. By clicking on the desired symbol it is taken into your program.

Training Centerfor Automation and Drives

ST-7PRO1SymbolsPage 12

Introduction If you want to change the assignments in the symbol table of an already existing l d id h th th b l t dd th b liprogram, you can also decide whether the absolute address or the symbolic

address has priority.

Selection In the SIMATIC Manager, select, with the right mouse button, the "Blocks" object of an S7 program. Select the menu option Properties and then the "Blocks“ tab.You can choose between "Absolute Value" or "Symbol" in the “Priority" field.

Priority: With this setting, the absolute address of an operand does not change, if youAbsolute Value change the address assignment in the symbol table later on. g g y

In the example above, the output Q8.0 (symbol name “Plant On") was changed to output Q4.0 in the symbol table. With the “Priority: Absolute Value" setting, the program continues to use the output Q8.0.

Priority: Symbol With this setting, the absolute address of the operand is changed to the new entry in the symbol table.In the example above, the output Q8.0 (symbol name “Plant On") was changed to output Q4.0 in the symbol table. With the “Priority: Symbols“ setting, the address is changed from Q8.0 to Q4.0 throughout the entire program.Th h d dd l k it b l Th t h thThe changed address also keeps its symbol name. That way you can change the absolute addresses in an existing symbolic user program.

Training Centerfor Automation and Drives

ST-7PRO1SymbolsPage 13

Goal To create a symbol table representing the first part of the filling application.

What to Do Create a symbol table for the FC 15 function in the S7 program "FILL":1. Open the Symbol Editor in the LAD/STL/FBD Editor by selecting the menu

options Options -> Symbol Table.2. Edit the symbol table, as is shown in the screen above. 3. Save the symbol table by selecting the menu options Symbol Table ->

Save and return to the LAD/STL/FBD Editor.4 Open the FC 15 block4. Open the FC 15 block5. Select the menu options View -> Display -> Symbolic Representation or

click the icon in the toolbar.

6. Look at your program in symbolic representation and then select the menu options View -> Display -> Symbol Information.

Result The symbolic names are now displayed for all the addresses in the program to which you have assigned names You can return to absolute addresses bywhich you have assigned names. You can return to absolute addresses by deactivating the Symbolic Representation selection in the View menu.

Training Centerfor Automation and Drives

ST-7PRO1SymbolsPage 14