Siemens SIMATIC S7-1500 System Manual page 160

Types of event sources
Removal/insertion of mod-
ules
Rack error
MC servo
4)
MC pre-servo
4)
MC post-servo
4)
MC interpolator
4)
MC PreInterpolator
4)
Programming error (only for
global error handling)
I/O access error (only for
global error handling)
If you have not configured the OB.
1)
For these event sources, apart from the permanently assigned OB numbers (see column: possible OB numbers), you
2)
can also assign OB numbers from the range ≥ 123 in STEP 7.
If the maximum cycle time has been exceeded twice within a cycle, the CPU always switches to STOP regardless of
3)
whether you have configured OB80.
You can find more information on these event sources and the startup behavior in the S7-1500 Motion Control function
4)
manuals.
Assignment between event source and OBs
The type of OB determines where you make the assignment between OB and event source:
● With hardware interrupts and isochronous mode interrupts, the assignment is made
during the configuration of the hardware or when the OB is created.
● For MC Servo, MC PreServo, MC PostServo, MC Interpolator and MC PreInterpolator,
STEP 7 automatically assigns OBs 91/92 as soon as you add a technology object.
● For all other types of OB, the assignment is made when the OB is created, where
applicable after you have configured the event source.
For hardware interrupts, you can change an assignment which has already been made
during runtime with the instructions ATTACH and DETACH. In this case, only the actually
effective assignment changes, and not the configured assignment. The configured
assignment takes effect after loading, and upon each startup.
The CPU ignores hardware interrupts to which you did not assign an OB in your
configuration or which occur after the DETACH instruction. The CPU does not check
whether an OB is assigned to this event when an event arrives, but only prior to the actual
processing of the hardware interrupt.
SIMATIC Drive Controller
System Manual, 11/2019, A5E46600094-AA
Possible priorities
(default priority)
2 to 26 (6)
2 to 26 (6)
17 to 26 (26)
Corresponds to MC Servo
priority
Corresponds to MC Servo
priority
16 to 25 (24)
Corresponds to MC Interpo-
lator priority
2 to 26 (7)
2 to 26 (7)
Possible OB num- Default system
bers reaction
83 Ignore
86 Ignore
91 Not applicable
67 Not applicable
95 Not applicable
92 Not applicable
68 Not applicable
121 STOP
122 Ignore
Basics of program execution
8.2 Events and OBs
Number of OBs
1)
0 or 1
0 or 1
0 or 1
0 or 1
0 or 1
0 or 1
0 or 1
0 or 1
0 or 1
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