Analog electronic modules
13
13.1
Behavior of the analog modules during operation and in the event of
problems
Influence of the power supply and the operating state
The input and output values of the analog modules are dependent on the supply voltage for
electronic components/sensors and on the operating mode of the PLC (CPU of the DP master).
Table 13-1
How the analog input/output values depend on the operating mode of the PLC (CPU of the DP master) and the
supply voltage L +
Operating mode of the
PLC (CPU of the DP
master)
Supply voltage L +
on ET 200iSP
(power supply
module)
Input value of the electronic module
with analog inputs (evaluation possi‐
ble in the CPU of the DP master)
Output value of the electronic module
with analog outputs
S7 format
POWER
ON
RUN
L+ present
Process values
PLC values
7FFF
H
until the first conversion after
switching on or after assigning param‐
eters to the module
Until the first value output:
● After startup, a signal of 0 V is
output.
● Dependent on the "Behavior at
CPU-Master-STOP" parameter
POWER
ON
STOP
L+ present
Process value
Dependent on the "Behavior at CPU-
Master-STOP" parameter
L+ missing
7FFF
H
-
Effect of the value range for the analog input
The behavior of the electronic modules with analog inputs depends on where the input values
are in the value range. The following table indicates this:
Table 13-2
Behavior of the analog modules depending on the position of the analog input value in the value range
Measured value within
Input value in the SIMATIC S7 format
Nominal range
Measured value
Overrange/underrange
Measured value
Overflow
7FFF
H
Underflow
8000
H
until valid measured values are available
7FFF
H
ET 200iSP
Operating Instructions, 11/2017, A5E00247483-07
269
