Siemens Simatic S7 Series

Program instructions
7.10 Interrupt
S7-200 SMART
282 System Manual, 09/2015, A5E03822230-AC
Offset
Field
Format
Type
Description
32 Previous process variable
(PV
n-1
)
REAL In/Out Contains the value of the process variable stored
from the last execution of the PID instruction.
36 to 79 Reserved for auto-tuning variables. Refer to PID loop definition table (Page 468) for details.
7.10
Interrupt
7.10.1
Interrupt instructions
When you make the transition to RUN mode, interrupts are initially disabled. In RUN mode,
you can enable interrupt processing by executing the ENI (enable Interrupt) instruction.
Executing the DISI (disable interrupt) instruction inhibits the processing of interrupts;
however, active interrupt events will continue to be queued.
ENI, DISI, and CRETI
LAD
FBD
STL
Description
ENI
The enable interrupt instruction globally enables processing of all attached inter-
rupt events.
DISI
The disable interrupt instruction globally disables processing of all interrupt
events.
CRETI
The conditional return from interrupt instruction can be used to return from an
interrupt, based upon the condition of the preceding program logic.
Non-fatal errors with ENO = 0
SM bits affected
• 0004H Attempted ENI or DISI exe-
cution disallowed in an interrupt
routine
None