Programming Instruction Lists (IL)

Programming Instruction Lists (IL) 1:

If required, IL can be enabled via the TwinCAT options. (Tools > Options > TwinCAT > PLC programming environment > FBD, LD and IL > IL)

Creating a POU in the Instruction List implementation language (IL)

1. Select a folder in the Solution Explorer in the PLC project tree.
2. In the context menu select the command Add > POU...
The Add POU dialog opens.
3. Enter a name and select the implementation language Instruction List (IL).
4. Click on Open.
TwinCAT adds the POU to the PLC project tree and opens it in the editor. A network has already been added in the implementation part.

Programming a network (e.g. for an ADD operation)

A POU (IL) is opened in the editor with an empty network.
1. Click in the 1st column of the highlighted row and enter the operator LD.
2. Press the [Tab] key.
The cursor jumps to the 2nd column.
3. Enter the first summand of your ADD operation, e.g. “6”.
4. Press [Ctrl] + [Enter] or select the command Insert IL line below in the menu FBD/LD/IL.
TwinCAT adds a new statement line at the bottom. The focus is in the first column of this row.
5. Enter ADD and press [Tab].
6. Enter the 2nd summand of your ADD operation, e.g. “12”.
7. Press [Ctrl] + [Enter]
8. Enter the operator ST and press [Tab].
9. Enter a variable of data type INT, e.g. “nVar”.
The result, in the example “16”, is stored in nVar.

See also:

Calling a function block

A POU (IL) is opened in the editor with an empty network. A variable with data type <function block>, is declared in the declaration part, e.g. fbSample : CTU;.
1. Click in the first column of the highlighted row and select the command Insert Box in the menu FBD/LD/IL.
The Input Assistant opens.
2. In the category Function blocks or Module calls select the required function block, for example the counter CTU from the library Tc2_Standard, and click OK.
3. TwinCAT adds the selected function block CTU as follows:
Programming Instruction Lists (IL) 2:
4. Replace the ??? strings with the variable names and the values or variables for the inputs/outputs of the function block.
5. As an alternative to adding the function block via the input assistant, you can enter the call directly in the editor.

See also: