In this task you will create a user-defined function block and then add input and output variables.
1. In the Project Organizer, right-click User-Defined Function Blocks, select Add, and then select New LD: Ladder Diagram.
2. Rename the Ladder Diagram UDFB:
Right-click UntitledLD and select Rename.
Type TRAFFIC_CONTROLLER_FB, and press Enter.
3. Under TRAFFIC_CONTROLLER_FB, double-click Local Variables to display the Local Variables grid as a tab in the workspace. Note the tab name (TRAFFIC_CONTROLLER_FB-VAR), which is the user-defined function block name with -VAR added to the end.
4. Arrange how columns appear in the Local Variables grid (optional):
Right-click the header row and click Hide Column to remove a column from the display
Click Show Column and select a column name to add a column
Click and hold a column header and drag it to an alternate location to move a column;
Click Reset Settings to display all the columns in the default layout.
5. If necessary, arrange the columns so they appear as shown in the following example.
6. Enter four input variables to represent a car sensor in each of the four positions in the intersection (N, S, E, W) as shown in the following table:
7. Enter six output variables to represent red, yellow and green traffic lights in each of two directions (NS, EW) as shown in the following table:
8. Verify your input and output variables are the same as those listed in the following the Local Variables grid example.
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1. In the Project Organizer, right-click User-Defined Function Blocks, select Add, and then select New LD: Ladder Diagram.
2. Rename the Ladder Diagram UDFB:
Right-click UntitledLD and select Rename.
Type TRAFFIC_CONTROLLER_FB, and press Enter.
3. Under TRAFFIC_CONTROLLER_FB, double-click Local Variables to display the Local Variables grid as a tab in the workspace. Note the tab name (TRAFFIC_CONTROLLER_FB-VAR), which is the user-defined function block name with -VAR added to the end.
4. Arrange how columns appear in the Local Variables grid (optional):
Right-click the header row and click Hide Column to remove a column from the display
Click Show Column and select a column name to add a column
Click and hold a column header and drag it to an alternate location to move a column;
Click Reset Settings to display all the columns in the default layout.
5. If necessary, arrange the columns so they appear as shown in the following example.
6. Enter four input variables to represent a car sensor in each of the four positions in the intersection (N, S, E, W) as shown in the following table:
7. Enter six output variables to represent red, yellow and green traffic lights in each of two directions (NS, EW) as shown in the following table:
8. Verify your input and output variables are the same as those listed in the following the Local Variables grid example.
Read More »