Siemens Simatic M7-400 Reference Manual page 200

Digital Modules
4.20.2 Behavior of the SM 422; DO 32
Effect of Operating Mode and Supply Voltage on the Output Values
The output values of the SM 422; DO 32
operating mode of the CPU and on the supply voltage of the module.
Table 4-19 Dependence of the Output Values on the Operating Mode of the CPU and on
the Supply Voltage L+ of the SM 422; DO 32
CPU Operating Mode
POWER ON
POWER
OFF OFF
Behavior in the Event of Failure of the Supply Voltage
The failure of the supply voltage of the SM 422; DO 32
indicated by the EXTF LED on the module. Furthermore, this information is made
available on the module (entry in diagnosis).
Triggering of the diagnostic interrupt depends on the parameter assignment (see
Section 4.20.1).
4-78
Power Supply L+
to Digital Module
RUN L+ exists
L+ missing
STOP
L+ exists
L+ missing
– L+ exists
L+ missing
S7-400, M7-400 Programmable Controllers Module Specifications
24 VDC/0.5 A
24 VDC/0.5 A depend on the
24 VDC/0.5 A
Output Value of Digital
Module
CPU value
0 signal
Substitute value/last value (0
signal preset)
0 signal
0 signal
0 signal
24VDC/0.5 A is always
A5E00069467-07