Basics of program execution
7.3 Events and OBs
S7-1500R/H redundant system
System Manual, 10/2018, A5E41814787-AA
153
7.3
Events and OBs
Start events
The table below gives an overview of the possible event sources for start events and their
OBs:
Table 7- 2
Start events
Event sources
Possible priorities (default
priority)
Possible OB num-
bers
Default system
response
1)
Number of OBs
Startup
1
100,
≥
123
Ignore
0 to 100
Cyclic program
1
1, ≥
123
Ignore
0 to 100
Time-of-day interrupt
2 to 24 (2)
10 to 17, ≥
123
Not applicable
0 to 20
Time-delay interrupt
2 to 24 (3)
20 to 23, ≥
123
Not applicable
0 to 20
Cyclic interrupt
2 to 24 (8 to 17, frequency
dependent)
30 to 38, ≥
123
Not applicable
0 to 20
Hardware interrupt
2 to 26 (18)
40 to 47, ≥
123
Ignore
0 to 50
CPU redundancy error
2 to 26 (26)
72
Ignore
0 or 1
Time error
22
80
Ignore
0 or 1
Maximum cycle time exceed-
ed
Depends on sys-
tem state
2)
Diagnostics interrupt
2 to 26 (5)
82
Ignore
0 or 1
Removal/insertion of mod-
ules
2 to 26 (6)
83
Ignore
0 or 1
Rack error
2 to 26 (6)
86
Ignore
0 or 1
Programming error (only for
global error handling)
2 to 26 (7)
121
STOP
0 or 1
I/O access error (only for
global error handling)
2 to 26 (7)
122
Ignore
0 or 1
1)
If you have not configured the OB.
2)
See section "Response of S7-1500R/H redundant system when cycle time is exceeded"
Response to start events
The occurrence of a trigger results in the following response:
●
If the event comes from an event source to which you have assigned an OB, this event
triggers the execution of the assigned OB. The event enters the queue according to its
priority (exception: hardware interrupts).
●
If the event comes from an event source to which you have not assigned an OB, the
default system response is executed.
Note
Some event sources, such as startup, pull/plug, exist even if you do not configure them.
Summary of Contents for Simatic S7-1500H
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