CPU 410-5H Process Automation
System Manual, 09/2014, A5E31622160-AB
121
Link-up and update
8
8.1
Effects of link-up and updating
Link-up and updating are indicated by the REDF LEDs on the two 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, PG 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
Test and commissioning
functions, such as "Monitor
and modify variable", "Moni-
tor (On/Off)"
Test and commissioning func-
tions are disabled.
When such actions are busy,
link-up and update operations
are inhibited.
Test and commissioning functions
are disabled.
Handling of the 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 the 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.