Arrangement Of The Process Data In The Paa/Pae - WAGO I/O-SYSTEM 750 Manual

110 Function Description
The fieldbus coupler writes the input process data received from the I/O modules
into the PAE. The input process data are sent in the next fieldbus cycle from the
fieldbus coupler to the EtherCAT
7.5.1

Arrangement of the Process Data in the PAA/PAE

The input and output data from the I/O modules are arranged by the fieldbus in
the process images according to a fixed schematic. The physical arrangement of
the I/O modules on a fieldbus node is arbitrary. The order in which the data of the
connected I/O modules is arranged depends on the type of I/O module (input
module, output module, etc).
Initially the byte-oriented I/O modules corresponding to the insertion order behind
the fieldbus coupler/controller are considered in the process images. The process
data from these I/O modules are therefore arranged beginning with word 2 in the
process images.
Then the data from the digital I/O modules is processed. This follows the
insertion order, whereby byte by byte is filled with data. As soon as a complete
byte is occupied by the process data of a bit-oriented I/O module, the process
begins automatically with the next byte.
The layout of the fieldbus coupler's process images is generated depending on
the I/O module configuration. The fieldbus coupler arranges the control and
status information in front of the process data in the PAA and/or PAE.
The following figure shows the arrangement of the process data and also the
arrangement of the control and status information in the PAA and/or PAE.
The number of words for output process data and input process data is equal in
the example presented, therefore the structure of the input and output data is
symmetrical. When the number of words for output and input process data is
different, then the structure of the process data is correspondingly asymmetrical.
Manual
Version 1.2.1
750-354/000-001 EtherCAT® Fieldbus Coupler, ID Switch
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master.
WAGO-I/O-SYSTEM 750