FBD/LD/IL Editor in Online Mode

FBD/LD/IL editor in online mode

In online mode the current value of each variable is displayed behind the variable in the editor. Writing/forcing and the setting of breakpoints is possible.

If the variable is presently forced, this is indicated directly in front of the forced value by . If a value has been prepared for writing or forcing, this value is displayed directly behind the current value in square brackets <value>.

Example

Forced variable:

Prepared value

In the online view of a ladder diagram (LD) the connecting lines are marked in color: connections with the value TRUE are displayed as a thick blue line, connections with the value FALSE as a thick black line. Conversely, connections with an unknown or analog value are displayed normally (thin black line).

Hint

Note that values of the connections are calculated from the monitored variables. This is not a genuine flow control.

Breakpoints

Possible positions for breakpoints are in principle the positions at which values of variables can change (instructions), at which the program branches or at which another box is called.

Possible breakpoint positions:

  • On the entire network: causes the breakpoint to be set at the first possible position in the network.

  • On a box, if the box contains an assignment. Not possible with operator boxes, for example ADD, DIV.

  • On assignments.

  • At the end of the box at the position of the return to the calling box. In online mode an empty network automatically appears here; it is marked by ‘RET’ in place of a network number.

Hint

At present you cannot directly set a breakpoint on the first box in the network. However, if you set a breakpoint on the entire network, this breakpoint marking is transferred automatically to the first box in online mode.

Hint

Breakpoints in methods: CODESYS automatically sets a breakpoint in all methods that can be called. Therefore, if a method managed by an interface is called, breakpoints are set in all methods that occur in function blocks that implement this interface as well as in all derived function blocks that use the method. If a method is called by a pointer to a function block, CODESYS sets the breakpoints in the method of the function block and in all derived function blocks that use the method.

See also