107BOnline and diagnostic tools
14.10 Monitoring and modifying values in the CPU
S7-1200 Programmable controller
642
System Manual, 11/2011, A5E02486680-05
Right-click an object in the "Compare to" column and
select "Start detailed comparison" button to show the
code blocks side-by-side.
The detailed comparison highlights the differences
between the code blocks of online CPU and the code
blocks of the CPU in your project.
14.10
Monitoring and modifying values in the CPU
STEP 7 provides online tools for monitoring the CPU:
●
You can display or monitor the current values of the tags. The monitoring function does
not change the program sequence. It presents you with information about the program
sequence and the data of the program in the CPU.
●
You can also use other functions to control the sequence and the data of the user
program:
–
You can modify the value for the tags in the online CPU to see how the user program
responds.
–
You can force a peripheral output (such as Q0.1:P or "Start":P) to a specific value.
–
You can enable outputs in STOP mode.
Note
Always exercise caution when using control functions. These functions can seriously
influence the execution of the user/system program.
Table 14- 3 Online capabilities of the STEP 7 editors
Editor
Monitor
Modify
Force
Watch table
Yes
Yes
No
Force table
Yes
No
Yes
Program editor
Yes
Yes
No
Tag table
Yes
No
No
DB editor
Yes
No
No
14.10.1
Going online to monitor the values in the CPU
To monitor the tags, you must have an online connection to the CPU. Simply click the "Go
online" button in the toolbar.