Addressing Analog Modules - Siemens SIMATIC S7-1500/ET 200MP System Manual

Configuring
8.1 Configuring the CPU
Value status
The value status is additional binary information of a digital input or output signal. It is
entered simultaneously with the process signal in the process image input and provides
information about the validity of the input or output signal.
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 a digital 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.
You can find more information on evaluation and processing of the value status for fail-safe
digital modules in the SIMATIC Safety – Configuring and Programming
(https://support.automation.siemens.com/WW/view/en/54110126) manual.
Reference
More information on addressing and address allocation with value status can be found in the
manuals of the digital modules, and in the online help for STEP 7. 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).
8.1.2.3

Addressing analog modules

Introduction
The following section describes the addressing of the analog modules. In your user program,
you require the addresses of the channels of the analog module.
Analog module addresses
The address of an analog channel is always a word address. The channel address depends on
the module start address. STEP 7 automatically assigns the channel addresses during
configuration. Based on the module start addresses, STEP 7 assigns the channel addresses in
increasing sequence (in the following figure, the module start address is 256).
When you insert an analog module into a free slot, STEP 7 assigns a default address. You can
change the assigned default address in STEP 7.
200
: 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