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11.10.8 CoE Object layout
Perception software offers control on which RT
-
FDB channels are published to
the bus. Each RT
-
FDB channel that is flagged for publishing has an associated
“object” in the CoE. In EtherCAT
®
, each “object” in turn has two “variables”. The
table below shows the CoE object entry for an RT
-
FDB channel with
name ”SomeChannel”.
Object Variable Type Description
SomeChannel Status USINT Status=0, Value should be ignored
Status=1; Value is valid
SomeChannel Value LREAL The sample value for this channel
Note
When the “Status
’
” variable has the value “0”, the associated variable ‘”Value”
is undefined. An EtherCAT
®
master software application must ignore the
“Value” in that case!
The following events within a Genesis mainframe will set the “Status” value to
“0” (and invalidate the “Value”):
l
The Genesis mainframe is in “idle” mode (does not apply to all hard
-
coded
objects).
l
The value of the associated RT
-
FDB channel should be ignored (e.g. due
to an invalid “VNorm”).
l
No cycles are detected for asynchronous RT
-
FDB channels.
l
When EtherCAT
®
is in Static mode, all EtherCAT
®
channels that do not
have a Genesis channel mapped to it have the “Status” value set to “0”.
A Genesis EtherCAT
®
slave also has some hard
-
coded objects in its CoE object
dictionary. These objects and their meaning are listed in the following table.
GEN3t
I3995-3.1 en HBM: public 239