Siemens SIMATIC ET 200AL, System Manual

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Maintenance
9.5 Cleaning modules
Distributed I/O system
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System Manual, 08/2021, A5E31861578-AJ
Fail-safe values for F-modules
For F-modules with inputs, the F-system provides fail-safe values (0) for the safety program
when passivated. The fail-safe values are used instead of the process data at the F-DI.
For F-modules with outputs, the F-system transfers the fail-safe values (0) to the fail-safe
outputs during passivation. The fail-safe values are used instead of the output values of the
safety program. The fail-safe outputs are de-energized. this process is performed even if the
F-CPU goes to the STOP operating state.
It is not possible to set the parameters of fail-safe values.
The fail-safe values are used in the following dependencies for the channel involved or all
channels of the I/O module involved:
•
F-system used
• Type of error occurred
– Error in the F-I/O
– Channel fault
– Communication error
Re-integration of a fail-safe module or channel
The F-system changes from fail-safe values to process values automatically or after
acknowledgment in the safety program by the user. A detailed list of errors can be found in
the device manual of the F-module or in the STEP 7 online help.
Procedure after re-integration:
•
For an F-module with inputs, the process data pending at the F-DI is provided again to the
safety program.
• For an F-module with outputs, the output values provided by the safety program are
transferred again to the F-DQs.
Additional information on passivation and re-integration
For additional information on passivation and reintegration of F-I/O modules, refer to the
SIMATIC Safety – Configuring and Programming
( https://support.industry.siemens.com/cs/ww/en/view/54110126 ) manual.
Reaction of the F-module with inputs to communication errors
F-modules with inputs react differently to communication errors than to other errors.
When a communication error is detected, the current process values at the inputs of the
F-module remain set. No channels are passivated. The current process values are passivated
in the F-CPU.
9.5 Cleaning modules
When wired, ET 200AL modules comply with degree of protection IP65/IP67 and do not
require any cleaning. If you do have to clean the modules, then use a dry or damp cloth.
Please take care to comply with degree of protection IP65/67 when cleaning with liquids.