Basics Of Program Execution; Events And Obs - Siemens Simantic ET200SP System Manual

Basics of program execution

7.1

Events and OBs

Response to triggers
The occurrence of a start event 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 is positioned in a queue according
to its priority.
● If the event comes from an event source to which you have not assigned an OB, the CPU
executes the default system reaction.
Note
Some event sources, such as startup, pull/plug, exist even if you do not configure them.
The table below provides an overview of the start events, including the possible values for
OB priority, possible OB numbers, default system reaction and number of OBs. The table is
sorted in ascending order by OB numbers.
Types of event sources
Starting
2)
Cyclic program
2)
Time-of-day interrupt
2)
Time-delay interrupt
2)
Cyclic interrupt
2)
Hardware interrupt
2)
Status interrupt
Update interrupt
Manufacturer-specific or
profile-specific interrupt
Synchronous cycle interrupt
Time error
3)
Cycle monitoring time ex-
ceeded once
Diagnostics interrupt
Pull/plug interrupt for mod-
ules
Rack error
MC-servo
4)
150
Possible priorities (default
priority)
1
1
2 to 24 (2)
2 to 24 (3)
2 to 24 (8 to 17, frequency
dependent)
2 to 26 (18)
2 to 24 (4)
2 to 24 (4)
2 to 24 (4)
16 to 26 (21)
22
2 to 26 (5)
2 to 26 (6)
2 to 26 (6)
17 to 26 (25)
Possible OB num- Default system
bers response
100, ≥ 123 Ignore
1, ≥ 123 Ignore
10 to 17, ≥ 123 Not applicable
20 to 23, ≥ 123 Not applicable
30 to 38, ≥ 123 Not applicable
40 to 47, ≥ 123 Ignore
55 Ignore
56 Ignore
57 Ignore
61 to 64, ≥ 123 Ignore
80 Ignore
STOP
82 Ignore
83 Ignore
86 Ignore
91 Not applicable
System Manual, 12/2016, A5E03576849-AG
7
Number of OBs
1)
0 to 100
0 to 100
0 to 20
0 to 20
0 to 20
0 to 50
0 or 1
0 or 1
0 or 1
0 to 2
0 or 1
0 or 1
0 or 1
0 or 1
0 or 1
Distributed I/O system