Siemens SIMATIC S7-1500/ET 200MP System Manual page 203

Configuring
8.1 Configuring the CPU
Value status
The value status is additional binary information of an analog input or output value. It is
entered simultaneously with the process value in the process image input and provides
information about the validity of the analog value.
The value status of a module informs you whether the value of the corresponding channel
can be read or output. You can respond to this information with simple binary operations in
the user program without having to evaluate the diagnostics information of the module for
this. Configured diagnostics in STEP 7 is not necessary for output of the value status.
If you enable the value status for an analog module, then additional bytes are allocated in the
input address area. Each bit in the value status is assigned to a channel and provides
information about the validity of the process value. You can find the assignment in the
product manual for the respective I/O module.
The value status is influenced by all diagnostics that might falsify the process value, e.g. wire
break, short-circuit.
• 1
• 0
or inaccessible.
Reference
More information on addressing and address allocation with value status can be found in the
manuals of the analog modules, and in the online help for STEP 7. A detailed description of
the value status for analog modules is available in the function manual Analog value
processing (https://support.automation.siemens.com/WW/view/en/67989094). An example of
the evaluation of the value status in the user program is available in the function manual
Diagnostics (https://support.automation.siemens.com/WW/view/en/59192926).
202
: A valid process value is being output or read for the channel.
B
: A substitute value is being output for the channel, or the channel is deactivated, faulty
B
Automation system
System Manual, 01/2023, A5E03461182-AK