Siemens SIMATIC ET 200S, Руководство пользователя

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Analog Electronic Modules
12-27
ET 200S Distributed I/O System
EWA-4NEB 780602402-12
Influence of the Power Supply and the Operating State
The input and output values of the analog modules are dependent on the power
supply for electronics/sensors and on the operating state of the PLC (CPU of the
DP master).
Table 12-27 Dependence of the Input and Output Values on the Operating State of the PLC (CPU of the
DP Master) and the Power Supply Voltage L +
Operating State
of the PLC (CPU
of the DP Master)
Power supply
L + at ET 200S
(power mod-
ule)
Input Value of the Electronics
Module with Analog Inputs
(Evaluation Possible on the
CPU of the DP Master)
Output Value of the Electron-
ics Module with Analog Out-
puts
POWER
ON RUN L + present Process values PLC values
ON
7FFF
H
until first conversion
after startup, or after
assignment of parameters for
the module is completed.
Until first value output:
•
After startup, a signal of 0 V
is output.
•
Dependent on the
parameter ”CPU/ master
STOP”
L + missing 7FFF
H
--
POWER
ON STOP L + present Process value Dependent on the parameter
”CPU/ master STOP”
L + missing 7FFF
H
--
POWER
OFF -- L + present -- Dependent on the parameter
”CPU/ master STOP”
L + missing -- --
Influence of the Value Range on the Analog Input
The response of the electronics modules with analog inputs depends on the part of
the value range in which the input values are located. The following table 12-28
illustrates the relationship.