Using Watchlists
What is a watch list?
A watch list is a user-defined list of project variables that are collected in a view for the purpose of monitoring their values. You can write and force variable values in a watch list in online mode.
Four watch lists Watch <n> are available for filling in the menu PLC > Windows in a project.
Creating and editing a watch list (offline or online mode)
- A project is opened in offline or online mode. Variables are declared in the project that you wish to have in one of the four watch lists.
- 1. Select the command Watch <n> in the menu PLC > Windows.
- The view Watch <n> appears. It contains an empty table row.
- 2. After double-clicking on the field in the column Expression, enter a variable to be monitored either manually or using the Input Assistant.
Syntax: <Device name>.<Project name>.<Object name>.<Variable name>
Example: „TwinCAT_Device.Project5.MAIN.nVar“
If you enter the name of a structured variable, the individual components will be displayed automatically in further rows in online mode. - 3. One after the other, define all the variables to be monitored with this list. You can change the order with drag-and-drop.
- The fields Execution point, Type, Address, Comment and Value are populated automatically according to the variable declaration. The symbol in front of the expression indicates whether the variable is an input variable, an output variable or a "normal" variable.
In online mode you can also create a new watch list or edit an existing one with the aid of the context menu command Add Watch. |
See also:
- TC3 User Interface documentation: Command Watch List <n>
Addition of variables with the help of the command Add Watch (online mode)
- A project is open in operation. Variables that you wish to place in a watch list are already declared in the project.
- 1. Open the desired watch list with the command Watch <n> in the menu PLC > Windows.
- 2. Place the cursor on the variable in the declaration or implementation part of a POU and select the command Add Watch from the context menu.
- An entry for the selected variable is added to the list.
- 3. You can add further variables in this way or by entering them in the list in the field Expression, as described above (Creating and editing a watch list).
- The watch lists are updated immediately.
If no watch list is open when you apply the command Add Watch to a variable, this is added automatically to the list "Watch 1". |
The writing and forcing of variable values is also possible in the watch lists. The column Prepared value appears for this in online mode. |
See also:
- Forcing and Writing Variables Values
- TC3 User Interface documentation: Command Watch List <n>
- TC3 User Interface documentation: Command Add to Watch