Designing a Sequential Control System based on the Example of a Drill
S7-GRAPH for S7 300/400 Programming Sequential Control Systems
3-20
C79000-G7076-C526-01
Setting the Mode
If you click one of the round option buttons, you switch the sequencer to the
selected mode.
You can, for example, run your sequencer in the manual mode instead of the
automatic mode. In the manual mode, you can activate or deactivate any step.
Follow the steps outlined below:
1. Enter the step number of the step you want to process in the "Step number" box
or simply click the required step.
2. Select the action to be executed with the step:
-
Activate The selected step is activated even if the preceding transition is not
satisfied.
-
Deactivate The selected step is deactivated.
Note that before you activate a step you must first deactivate the currently active
step since only one step can be active at any one time in a linear sequencer. In
other words, you can only activate the required step when you have deactivated
the currently active step.
If you have set a new mode, the original mode is indicated in bold face.
After you have controlled your sequencer in the manual mode, you can return to
the automatic mode and close the "Control Sequencer" dialog box.
3.15
Changing the Sequencer
Often, a program does not run as required at the first attempt. This means that
changes and modifications are required. This is also the case in our sample
program. The configured monitoring time in Step 2 is too short and the program
hangs at this step. The following section explains how to make the required
changes. You must first change to the "offline" mode.
Modifying the Monitoring Time
The monitoring time configured in Step 2 is 500 ms. To give you more time for
setting the "Cl_press_ok" variable, change the monitoring time to 5 s as explained
below:
1. Double-click step 2 to change from the “single page" display to the “single step"
display.
2. Close the status by selecting the menu command Debug
>
Monitor or clicking
the following button:
.
3. Enter the value 5 s for the monitoring time.
4. Save the sequencer with the menu command File
>
Save, since the sequencer
must be recompiled.