216 • The Editors

The Graphic Editors

When this command is selected the first thing to happen is that the elements are ordered topographically. A new sequential processing list is then created. Based on the known values of the inputs, the computer calculates which of the as yet not numbered elements can be processed next. In the above "network" the block AND, for example, could be processed immediately since the values at its inputs (1 and 2) are known. Block SUB can only then be processed since the result from ADD must be known first, etc.

Feedback paths are inserted last.

The advantage of the data flow sequencing is that an output box which is connected to the output of a block comes immediately after it in the data flow sequencing system which by topological ordering would not always be the case. The topological ordering can deliver another result in some cases than ordering by data flow, a point which one can recognise from the above example.

5.4.5.31'Extras' 'Create macro''

Symbol:

With this command, several POUs that are selected at the same time can be assembled into a block, which can be named as a macro. Macros only can be reproduced by Copy/Paste, whereby each copy becomes a separate macro whose name can be chosen independently. Macros are thus not references. All connections that are cut by the creation of a macro generate inor out-pins on the macro. Connections to inputs generate an in-pin. The default name appears

WAGO-I/O-SYSTEM 759 WAGO-I/O-PRO 32

The Editors • 217

The Graphic Editors

next to the pin in the form In<n>. For connections to outputs, Out<n> appears. Affected connections which had connection markers prior to the creation of the macro, retain the connection marker on the PIN of the macro.

At first, a macro has the default name "MACRO". This can be changed in the Name field of the macro use. If the macro is edited, the name of the macro will be displayed in the title bar of the editor window appended to the POU name.

Example:

Selection

Macro:

In the editor:

5.4.5.32'Extras' 'Jump into Macro'

Symbol:

WAGO-I/O-SYSTEM 759 WAGO-I/O-PRO 32

218 • The Editors

The Graphic Editors

By this command, or by double clicking on the body of the macro, the macro is opened for editing in the editor window of the associated POU. The name of the macro is displayed appended to the POU name in the title bar.

The pin boxes generated for the inand outputs of the macro during creation can be handled like normal POU inand outputs. They can also be moved, deleted, added, etc. They differ only in how they are displayed and have no

position index. For adding you can use the buttons (input) resp.

(output), which are available in the menu bar. Pin boxes have rounded corners. The text in the pin-box matches the name of the pin in the macro display.

The order of the pins in the macro box follows the order of execution of the elements of the macro. A lower order index before a higher one, higher pin before lower.

The processing order within the macro is closed, in other words the macro is processed as a block, at the position of the macro in the primary POU. Commands for manipulating the order of execution therefore operate only within the macro.

5.4.5.33'Extras' 'Expand macro'

With this command, the selected macro is re-expanded and the elements contained in it are inserted in the POU at the macro's location. The connections to the pins of the macro are again displayed as connections to the inor outputs of the elements. If the expansion of the macro can not occur at the location of the macro box for lack of space, the macro is displaced to the right and down until enough space is available.

Note:

If the project is saved under project version number 2.1, the macros will likewise all be expanded. All macros will also be expanded before conversion into other languages.

5.4.5.34'Extras' 'Back one macro level', 'Extras' 'Back all macro level'

Symbols:

These commands are also available in the toolbar, as soon as a macro is opened for editing. If macros are nested within one another, it is possible to switch to the next higher or to the highest display level.

5.4.5.35Feedback paths in CFC

Feedback paths can only be displayed directly in the continuous function chart editor and not in the usual function block diagram editor. Here it should be observed that the output of a block always carries an internal intermediate variable. The data type of the intermediate variable results, for operators, from the largest data type of the inputs.

WAGO-I/O-SYSTEM 759 WAGO-I/O-PRO 32

The Editors • 219

The Graphic Editors

The data type of a constant is obtained from the smallest possible data type, that is the constant '1' adopts the data type SINT. If now an addition with feedback and the constant '1' is executed, the first input gives the data type SINT and the second is undefined because of the feedback. Thus the intermediate variable is also of the type SINT. The value of the intermediate variable is only then allocated to the output variable.

The diagram below shows an addition with feedback and an addition with a variable. The variables x and y should be of the type INT here.

There are differences between the two additions:

The variable y can be initialised with a value which is not equal to zero but this is not the case for intermediate variable for the left addition.

The intermediate variable for the left addition has the data type SINT while that on the right has the data type INT. The variables x and y have different values after the 129th call up. The variable x, although it is of the type INT, contains the value - 127 because the intermediate variable has gone into overflow. The variable y contains the value 129, on the other hand.

5.4.5.36CFC in Online mode

Monitoring:

The values for inputs and outputs are displayed within the input or output boxes. Constants are not monitored. For non-boolean variables, the boxes are expanded to accommodated the values displayed. For boolean connections, the variable name as well as the connection are displayed in blue if the value is TRUE, otherwise they remain black.

Internal boolean connections are also displayed Online in blue in the TRUE state, otherwise black. The value of internal non-boolean connections is displayed in a small box with rounded corners on the output pin of the connection.

PINs in macros are monitored like inor output boxes.

WAGO-I/O-SYSTEM 759 WAGO-I/O-PRO 32

220 • The Editors

The Graphic Editors

Non-boolean connections with connection markers display their value within the connection marker. For boolean connections, the lines as well as the marker names are displayed in blue if the line is carrying the value TRUE, otherwise black.

Flow control:

When flow control is switched on, the connections that have been traversed are marked with the color selected in the project options.

Breakpoints:

Breakpoint s can be set on all elements that also have a processing sequence order index. The processing of the program will be halted prior to execution of the respective element, that is for POUs and outputs before the assignment of inputs, for jump labels before execution of the element with the next index. The processing sequence index of the element is used as the breakpoint position in the Breakpoint dialog.

The setting of breakpoints on a selected element is accomplished with the F9 key or via the menu item 'Breakpoint on/off' in the 'Online' or 'Extras' menu or in the editor's context menu. If a breakpoint is set on an element, then this will be erased and reversed the next time the command 'Breakpoint on/off' is executed. In addition, the breakpoint on an element can be toggled by doubleclicking on it.

Breakpoints are displayed in the colors entered in the project options.

RETURN label:

In Online mode, a jump label with the name "RETURN" is automatically generated in the first column and after the last element in the editor. This label marks the end of the POU and is jumped to when stepping just before execution leaves the POU. No RETURN marks are inserted in macros.

Stepping:

When using 'Step over' the element with the next-higher order index will always be jumped to. If the current element is a macro or a POU, then its implement branches when 'Step in' is in effect. If a 'Step over' is executed from there, the element whose order index follows that of the macro is jumped to.

WAGO-I/O-SYSTEM 759 WAGO-I/O-PRO 32