II - DCE FEL ČVUT v Praze

Interrupts
Parameterizing
interrupts
Default setting
Diagnostic
interrupt
Influence of
supply voltage and
operating status
I/O Modules with Intrinsically-Safe Signals
C79000-G7076-C152-04
The digital output can trigger a diagnostic interrupt.
Interrupts are parameterized with STEP 7.
The interrupts are inhibited as the default.
If enabled, the module triggers a diagnostic interrupt when a fault is
recognized or is no longer applicable (e.g. short to M). diagnostic functions
inhibited by parameterization cannot trigger an interrupt. The CPU interrupts
processing of the user program or low-priority classes and processes the
diagnostic interrupt module (OB 82).
The output values are dependent on the supply voltages and CPU operating
status.
Table 2-13 provides an overview of these dependencies.
Table 2-13 Dependencies of output values on the CPU operating status and supply
voltage L+ of SM 322; DO 4 x 24V/10mA and
SM 322; DO 4 x 15V/20mA
Operating status
CPU
Supply voltage L+ at
digital module
SIMATIC S7 Ex Digital Modules
POWER ON RUN L+ applied CPU value
L+ not applied 0-signal
Output value of digital
module
STOP L+ applied Substitute value / last
value
Substitute value for
0-signal is default setting
L+ not applied 0-signal
POWER OFF – L+ applied 0-signal
L+ not applied 0-signal
Failure of the supply voltage in the SM 322; DO 4 x 24V/10mA is always
indicated by the SF LED on the front of the module and additionally entered
in diagnostics.
2-23