System description - Pilz GmbH & Co.

Modules
Analogue input/output (failsafe)
PSSu E F AI U(-T)
Block diagram
Blockschaltbild
11 14
Periphery
Supply
+ 24 V DC
Input
Module Bus
Module
Supply
+ 5 V DC
ADC
Data
(FS)
C-Rail
13 23
Function description
][Funktionsbeschreibung Supply
Module supply
The module supply provides the
module with voltage.
][Funktionsbeschreibung BA Signalverarbeitung FS-AI
Input signal processing
The analogue input signal is prefiltered,
amplified and stored as a
digital measured value.
A "dynamised" value is also generated.
This value is formed from the
sum of the measured value and a
test value.
For the feasibility check, the test
value is subtracted from the measured
value. The measured value
that has been read in is then compared
with the "dynamised" value.
The feasibility of the value is
checked in the head module. It is
feasible if it varies at most by a
small, defined tolerance value.
If the difference between the two
values lies within a certain tolerance,
the measured value is valid. If
the difference lies outside that tolerance,
the measured value will be rerecorded.
If this value also lies outside
the tolerance, an error message
will be issued.
3.7
][Funktionsdiagramm FS-AI
Schematic representation of signal processing:
Analogue
Digital
Input
Analogue
Digital
Microcontroller
FS
module
bus
Head
module
][Funktionsbeschreibung BA Auflösung FS-AI U
Pilz GmbH & Co. KG, Felix-Wankel-Straße 2, 73760 Ostfildern, Germany
Telephone: +49 711 3409-0, Telefax: +49 711 3409-133, E-Mail: pilz.gmbh@pilz.de
PSSu-2011-01
3.7-13