Beckhoff EL6751 Documentation page 67

Fig. 80: Selection of the diagnostic information of an EtherCAT Slave
In general, an EtherCAT Slave offers
• communication diagnosis typical for a slave (diagnosis of successful participation in the exchange of
process data, and correct operating mode)
This diagnosis is the same for all slaves.
as well as
• function diagnosis typical for a channel (device-dependent)
See the corresponding device documentation
The colors in Fig. "Selection of the diagnostic information of an EtherCAT Slave" also correspond to the
variable colors in the System Manager, see Fig. "Basic EtherCAT Slave Diagnosis in the PLC".
Colour Meaning
yellow Input variables from the Slave to the EtherCAT Master, updated in every cycle
red Output variables from the Slave to the EtherCAT Master, updated in every cycle
green Information variables for the EtherCAT Master that are updated acyclically. This means that
it is possible that in any particular cycle they do not represent the latest possible status. It is
therefore useful to read such variables through ADS.
Fig. "Basic EtherCAT Slave Diagnosis in the PLC" shows an example of an implementation of basic
EtherCAT Slave Diagnosis. A Beckhoff EL3102 (2-channel analogue input terminal) is used here, as it offers
both the communication diagnosis typical of a slave and the functional diagnosis that is specific to a channel.
Structures are created as input variables in the PLC, each corresponding to the process image.
EL6751
Parameterization and commissioning
Version: 3.5 67