All ladder programs use function in addition to the basic instruction. These are entered in much the same way as symbols, but because most of them require data parameters on which to operate, the process involves different dialogs.
SYSWIN uses your setting of the PLC type, together with your function mapping parameters to determine which functions are available to use. When a function is selected, a dialog box is displayed requesting the necessary data.
If you know which function you wish to insert in a network, the easiest way to enter it is to use the ‘F’ key. This displays the function dialog box, and you can type in the name or number of the function.
When a function is drawn, its inputs (and occasionally output) are indicated by unterminated lines. These need to be connected to other parts of the network before the network is complete.
Most functions are available in differentiated and non-differentiated forms. They identified by special symbols in front of the name. When a function can have more than one form, the dialog provides extra check boxes. Alternatively, you can use special characters when typing a function name, and SYSWIN converts the function as appropriate:
• @ Differentiate UP
• % Differentiate DOWN
• ! Immediate refresh
The availability of differentiated functions, contacts and outputs depends on the PLC type.