Siemens Simatic S7-400 - Manual (Page 135)

Digital Modules
4-13
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
4.5 Interrupts of the Digital Modules
Introduction
This section describes the interrupt behavior of the digital modules. The following
interrupts exist:
• Diagnostic Interrupt
• Hardware interrupt
Note that not all digital modules have interrupt capability or they are only capable of
a subset of the interrupts described here. Refer to the technical specifications of
the modules, starting at Section 4.7, to find out which digital modules have interrupt
capability.
The OBs and SFCs mentioned below can be found in the online help system for
STEP 7, where they are described in greater detail.
Enabling Interrupts
The interrupts are not preset – in other words, they are inhibited without
appropriate parameter assignment. You enable the interrupts in STEP 7
(refer to Section 5.7).
Special Feature: The Module is Inserted in ER-1/ER-2
Note
If you use the digital module in ER-1/ER-2, you must set the parameters for
enabling all the interrupts to “No” because the interrupt lines are not available in
ER-1/ER-2.
Diagnostic Interrupt
If you have enabled diagnostic interrupts, then active error events (initial
occurrence of the error) and departing error events (message after troubleshooting)
are reported by means of an interrupt.
The CPU interrupts the execution of the user program and processes the
diagnostic interrupt block (OB 82).
In the user program, you can call SFC 51 or SFC 59 in OB 82 to obtain more
detailed diagnostic information from the module.
The diagnostic information is consistent until such time as OB 82 is exited. When
OB 82 is exited, the diagnostic interrupt is acknowledged on the module.