Technical data

Testing with the Variable Table
20.6 Monitoring Variables
Programming with STEP 7
458 Manual, 05/2010, A5E02789666-01
Trigger Point
The following figure shows the position of the trigger points.
To display the modified value in the "Status Value" column, you should set the trigger point for
monitoring to "Start of cycle" and the trigger point for modifying to "End of cycle".
Trigger Immediately
You can update the values of selected variables using the menu command Variable > Update
Monitor Values. This command is taken to mean "trigger immediately" and is executed as quickly
as possible without reference to any point in the user program. These functions are mainly used for
monitoring and modifying in STOP mode.
Trigger Frequency
The following table shows the effect that the trigger frequency has on the monitoring of variables:
Trigger frequency: Once Trigger frequency: Every cycle
Monitor
Variables
Update once
Dependent on trigger point
Monitoring with a defined trigger
When testing a block you can track the progress
of processing exactly.