PLC Programming

The Graphic Editors...
x will be increased by one until it reaches the value 10. This causes the output of the block LT(0) to
deliver the value FALSE and SUB(3) and ADD(5) will be executed. x is set back to the value 1 and y
is increased by 1. LT(0) is executed again as long as x is smaller than 10. y thus count the number of
times x passes though the value range 1 to 10.
'Extras' 'Properties...' in CFC
Constant input parameters (VAR_INPUT CONSTANT) from functions and function blocks are not
shown directly in the continuous function chart editor. These can be shown and their value can be
changed when one selects the trunk of the block in question and then selects the command ‚Extras'
‚Properties' or simply double clicks on the trunk. The „Edit parameters" dialog opens:
Properties dialog
The values of the constant input parameter (VAR_INPUT CONSTANT) can be changed. Here it is
necessary to mark the parameter value in the column Value. Another mouse click or pressing on the
space bar allows this to be edited. Confirmation of the change to the value is made by pressing the
key or pressing rejects the changes. The button OK stores all of the changes
which were made.
Selecting elements in CFC
One clicks on the trunk of the element to select it.
To mark more elements one presses the key and clicks in the elements required, one after the
other, or one drags the mouse with the left hand mousekey depressed over the elements to be
marked.
The command 'Extras' 'Select all' marks all elements at once.
Moving elements in CFC
One or more selected elements can be moved with the arrow keys as one is pressing on the
key. Another possibility is to move elements using a depressed left mousekey. These elements are
placed by releasing the left mousekey in as far as they do not cover other elements or exceed the
foreseen size of the editor. The marked element jumps back to its initial position in such cases and a
warning tone sounds.
Copying elementsin CFC
One or more selected elements can be copied with the command 'Edit' 'Copy' and inserted with the
command 'Edit' 'Paste'.
Changing connections
A connection between the output of an element E1 and the input of an element E2 can easily be
changed into a connection between the output of element E1 and the input of element E3. The mouse
is clicked on the input of E2, the left mousekey is kept depressed, the mouse cursor is moved to the
input of E3 and then released.
5-40 CoDeSys V2.3