BECKHOFF EL7037 - Manual (Page 93)

Commissioning
Code Function Implementation Application/evaluation
A The EtherCAT Master's
diagnostic information
updated acyclically (yellow) or
provided acyclically (green).
At least the DevState is to be
evaluated for the most recent cycle
in the PLC.
The EtherCAT Master's diagnostic
information offers many more
possibilities than are treated in the
EtherCAT System Documentation.
A few keywords:
• CoE in the Master for
communication with/through
the Slaves
• Functions from
TcEtherCAT.lib
• Perform an OnlineScan
B In the example chosen (EL3102)
the EL3102 comprises two
analogue input channels that
transmit a single function status
for the most recent cycle. Status
• the bit significations
may be found in the
device documentation
• other devices may
supply more
information, or none
that is typical of a
slave
In order for the higher-level PLC
task (or corresponding control
applications) to be able to rely on
correct data, the function status
must be evaluated there. Such
information is therefore provided
with the process data for the most
recent cycle.
C For every EtherCAT Slave that
has cyclic process data, the
Master displays, using what is
known as a WorkingCounter,
whether the slave is participating
successfully and without error in
the cyclic exchange of process
data. This important, elementary
information is therefore provided
for the most recent cycle in the
System Manager
1. at the EtherCAT Slave,
and, with identical contents
2. as a collective variable at
the EtherCAT Master (see
Point A)
for linking.
WcState (Working Counter)
0: valid real-time
communication in the last
cycle
1: invalid real-time
communication
This may possibly have
effects on the process data
of other Slaves that are
located in the same
SyncUnit
In order for the higher-level PLC
task (or corresponding control
applications) to be able to rely on
correct data, the communication
status of the EtherCAT Slave must
be evaluated there. Such
information is therefore provided
with the process data for the most
recent cycle.
EL70x7 93 Version 1.0