101BExtended instructions
8.4 Interrupts
S7-1200 Programmable controller
System Manual, 11/2011, A5E02486680-05
281
Bit
Value
Description
0
An OB with an OB number given in OB_NR does not exist.
4
1
An OB with an OB number given in OB_NR exists.
Other bits
Always 0
Condition codes
Table 8- 99 Condition codes for SRT_DINT, CAN_DINT, and QRY_DINT
RET_VAL (W#16#...)
Description
0000
No error occurred
8090
Incorrect parameter OB_NR
8091
Incorrect parameter DTIME
80A0
Time delay interrupt has not started.
8.4.4
Asynchronous event interrupts
Use the DIS_AIRT and EN_AIRT instructions to disable and enable alarm interrupt
processing.
Table 8- 100 DIS_AIRT and EN_AIRT instructions
LAD / FBD
SCL
Description
DIS_AIRT();
DIS_AIRT delays the processing of new interrupt events. You can execute
DIS_AIRT more than once in an OB.
EN_AIRT();
EN_AIRT enables the processing of interrupt events that you previously disabled
with the DIS_AIRT instruction. Each DIS_AIRT execution must be cancelled by an
EN_AIRT execution.
The EN_AIRT executions must occur within the same OB, or any FC or FB called
from the same OB, before interrupts are enabled again for this OB.
Table 8- 101 Data types for the parameters
Parameter and type
Data type
Description
RET_VAL
OUT
Int
Number of delays = number of DIS_AIRT executions in the queue.
The DIS_AIRT executions are counted by the operating system. Each of these remains in
effect until it is cancelled again specifically by an EN_AIRT instruction, or until the current OB
has been completely processed. For example: if you disabled interrupts five times with five
DIS_AIRT executions, you must cancel these with five EN_AIRT executions before interrupts
become enabled again.