CPU 410 Process Automation/CPU 410 SMART
System Manual, 05/2017, A5E31622160-AC
119
Link-up and update
8
8.1
Effects of link-up and updating
The link-up and update operations are indicated by the REDF LED on both CPUs. During
link-up, the LEDs flash at a frequency of 0.5 Hz, and when updating at a frequency of 2 Hz.
Link-up and update have various effects on user program execution and on communication
functions.
Table 8- 1
Properties of link-up and update functions
Process
Link-up
Update
Execution of the user pro-
gram
All priority classes (OBs) are
processed.
Processing of the priority classes is
delayed section by section. All re-
quests are caught up with after the
update.
For details, refer to the sections be-
low.
Deleting, loading, generat-
ing, and compressing of
blocks
Blocks cannot be deleted,
loaded, created or com-
pressed.
When such actions are busy,
link-up and update operations
are inhibited.
Blocks cannot be deleted, loaded,
created or compressed.
Execution of communication
functions, ES operation
Communication functions are
executed.
Execution of the functions is restrict-
ed section by section and delayed. All
the delayed functions are caught up
with after the update.
For details, refer to the sections be-
low.
CPU self-test
Not performed
Not performed
Testing and commissioning
functions, such as "Moni-
tor/modify tag", "Monitor
(on/off)".
No testing and commissioning
functions are possible.
When such actions are busy,
link-up and update operations
are inhibited.
No testing and commissioning func-
tions are possible.
Handling of connections on
the master CPU
All connections are retained;
no new connections can be
made.
All connections are retained; no new
connections can be made.
Interrupted connections are not re-
stored until the update is completed
Handling of connections on
the reserve CPU
All the connections are can-
celled; no new connections can
be made.
All connections are already down.
Cancellation takes place during link-
up. Connections of the standby are
not established until Redundant sys-
tem state.