Siemens SIMATIC CPU 410 System Manual page 163

After transmission of the data records, the IO controller marks the I/O modules in the module
status data as follows:
● When the transmission was successful, as available.
● When the transmission was not successful, as unavailable.
An I/O access error occurs when the I/O module is accessed:
– During the update of the input process image, during transmission of the output
– The input or output data of the I/O modules behaves in the same way as after a
Note
If the re-configuration of an I/O module involves disabling the diagnostic interrupt, for
example, the I/O module may still subsequently send an interrupt that it has already
prepared.
Re-configuring a port (PDEV submodule)
Ports are re-configured in the same way to I/O modules.
Possible fault scenarios during re-configuring
The following error scenarios are possible:
● The I/O module receives the parameter data records but cannot evaluate them.
● Serious errors, in particular protocol errors, may cause the IO controller to completely
suspend the associated IO device, causing all I/O modules of this station to fail.
Dependency of re-configuration on CPU operating states
Re-configuration takes place after SDB evaluation (see Behavior of the CPU after download
of the configuration in RUN) in RUN mode. The INTF-LED is on during re-configuration.
The re-configuration process is interrupted during transition to the HOLD operating state.
The process is continued when the CPU changes to STOP or RUN. In STOP only the calls
of OB83 are stopped.
Re-configuration is aborted if there is a power failure. Once power is restored, all existing IO
devices are re-configured.
CPU 410 Process Automation/CPU 410 SMART
System Manual, 05/2017, A5E31622160-AC
process image to the I/O module, or during direct access to the module. Depending on
the type of access, OB 85 or OB 122 is started.
remove module interrupt, which means it may not yet be correct (because the I/O
module may not yet have evaluated its data records).
However, the restriction that data record functions for the I/O modules can no longer
be active no longer applies.
11.4 Re-configuring I/O modules and ports in IO devices
Plant changes in RUN - CiR
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