Monitoring And Modifying I/Os - Siemens Simatic S7-300 CPU 31xC Series Installation And Operating Instructions Manual

Online Help
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8.4.7

Monitoring and modifying I/Os

The "Monitor and modify tags" tool
The STEP 7 "Monitor and modify tags" tool lets you:
• monitor program tags in any format
• edit the tag status or data in the CPU (modifying).
Creating a tag table
You have two options of creating a tag table (VAT):
• in the LAD / FBD / STL editor by selecting the PLC > Monitor/Modify Variables command
• in SIMATIC Manager with the Blocks container open via menu item Insert New Object >
VAT structure:
In the VAT, every address to be monitored or modified (e.g. inputs, outputs) occupies one
row.
The meaning of the VAT columns is as follows:
Column text
Address
Icon
Symbol comment
Status format
Status value
Modify value
S7-300, CPU 31xC and CPU 31x: Installation
Operating Instructions, Edition 08/2004, A5E00105492-05
This table is also available directly online.
Variable table
This table created offline can be saved for future retrieval. You can also test it after
switching to online mode.
This field ...
contains the absolute address of the variable
contains the symbolic descriptor of the variable.
This is identical to the specification in the Symbol Table.
shows the symbol comment of the Symbol Table
contains the default format setting, e.g. HEX.
You can change the format as follows:
right-click in the format field. The Format List opens.
•
or
left-click in the format field until the relevant format appears
•
shows the content of the variable at the time of update
is used to enter the new variable value (modify value)
Commissioning
8.4 Commissioning the Modules
8-19