Representation of the analog values of analog modules
5.4 Reactions of the analog modules
S7-300 Automation System Module data
5-24 Manual, 08/2006, A5E00105505-04
Influence of the supply voltage and operating state on the modules
The IO values of analog modules are determined by the CPU operating state and the
module's supply voltage.
Table 5-39 Dependencies of the analog IO values on the CPU's operating State and on the L+ supply voltage
CPU operating state Supply voltage L+
at the analog
module
Input value of the analog input
module
Output value of the analog output
module
Measured value CPU values L+ present
7FFF
H
, until the first conversion after
POWER ON is completed, or when
the module has been programmed.
Until the first conversion...
• after POWER ON, the module
outputs a 0 mA or 0 V signal.
• after programming is successfully
completed, it outputs the previous
value.
POWER
ON
RUN
L+ missing Overflow value 0 mA / 0 V
Measured value L+ present
7FFF
H
, until the first conversion after
POWER ON is completed, or when
the module has been programmed.
Substitution value / last value
(default: 0 mA / 0 V)
POWER
ON
STOP
L+ missing Overflow value 0 mA / 0 V
L+ present - 0 mA / 0 V POWER
OFF
-
L+ missing - 0 mA / 0 V
Reaction to power failure
Power failure at analog modules is always indicated by their relevant SF LED. This
information is also available on the module (in diagnostic buffer data.)
Diagnostics interrupt triggering is based on parameter settings.
See also
Programming analog modules (Page 5-31)