Effect Of Supply Voltage And Operating Mode - Siemens SIMATIC S7-400 Reference Manual

5.6.2

Effect of supply voltage and operating mode

Overview
The IO values of analog modules are determined by the CPU operating state and the module's
supply voltage.
Table 5-38 Dependencies of the analog IO values on the CPU's operating State and on the L+ supply voltage
CPU operating state
POWER RUN
ON
POWER STOP
ON
POWER -
OFF
* L+ only required with 2-wire sensors
Behavior on failure of the supply voltage
Failure of the load power supply L+ of the diagnostics-capable analog module is indicated in
the case of configured 2-wire sensors by the EXTF LED on the module. This information is
also available on the module (in the diagnostic buffer data.)
Diagnostics interrupt triggering is based on parameter settings.
See also
General information about parameter assignment (Page 199)
S7-400 Automation System Module Data
Reference Manual, Ausgabe 11/2016, A5E00850736-08
Supply voltage L+ at the an‐
alog module
L+ present
L+ missing
L+ present
L+ missing
L+ present
L+ missing
Output value of the
analog output module
CPU values
Until the first conversion...
● after power-up has been
completed, a signal of 0 mA or
0 V is output.
● after programming is
successfully completed, it
outputs the previous value.
0 mA / 0 V
Substitution value / last value
(default: 0 mA / 0 V)
0 mA / 0 V
0 mA / 0 V
0 mA / 0 V
Analog modules
5.6 Behavior of the analog modules
Input value of the
analog input module*
Measured value
7FFF , until the first conversion
H
after POWER ON is completed,
or when the module has been
programmed.
Measured value
7FFF , until the first conversion
H
after POWER ON is completed,
or when the module has been
programmed.
-
-
193