Communication in SIMATIC S7-300/1200/1500
11.11 Hardware interrupts
SIWAREX WP321
106 Manual, 07/2014, A5E33715669A-02
Figure 11-7 Configuration of hardware interrupts for S7-1500
You can use the hardware interrupts to detect changes in the status of limits. The change in
status is entered in the interrupt OB as EventType:
PRAL #1 Limit 1 OFF → ON
PRAL #2 Limit 1 ON → OFF
PRAL #3 Limit 2 OFF → ON
PRAL #4 Limit 2 ON → OFF