Automation system
178
System Manual, 12/2017, A5E03461182-AE
Basics of program execution
8
8.1
Events and OBs
Response to triggers
The occurrence of a trigger results in the following reaction:
●
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.
●
If the event comes from an event source to which you have not assigned an OB, the
default system reaction is executed.
Note
Some event sources, such as startup, pull/plug, exist even if you do not configure them.
Triggers
The table below provides an overview of:
●
possible event sources
●
possible values for the OB priority
●
possible OB numbers
●
default system reaction
●
Number of OBs
Table 8- 1
Triggers
Types of event sources
Possible priorities (default
priority)
Possible OB num-
bers
Default system
reaction
1)
Number of OBs
Startup
2)
1
100, ≥ 123
Ignore
0 to 100
Cyclic program
2)
1
1, ≥ 123
Ignore
0 to 100
Time-of-day interrupt
2)
2 to 24 (2)
10 to 17, ≥ 123
Not applicable
0 to 20
Time-delay interrupt
2)
2 to 24 (3)
20 to 23, ≥ 123
Not applicable
0 to 20
Cyclic interrupt
2)
2 to 24 (8 to 17, frequency
dependent)
30 to 38, ≥ 123
Not applicable
0 to 20
Hardware interrupt
2)
2 to 26 (18)
40 to 47, ≥ 123
Ignore
0 to 50
Status interrupt
2 to 24 (4)
55
Ignore
0 or 1
Update interrupt
2 to 24 (4)
56
Ignore
0 or 1
Manufacturer-specific or
profile-specific interrupt
2 to 24 (4)
57
Ignore
0 or 1
Summary of Contents for Simatic S7-1500/ET 200MP
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