Commissioning
EL10xx, EL11xx
67
Version: 4.5
Fig. 58: Display of previous revisions
Device selection based on revision, compatibility
The ESI description also defines the process image, the communication type between master and
slave/device and the device functions, if applicable. The physical device (firmware, if available) has
to support the communication queries/settings of the master. This is backward compatible, i.e.
newer devices (higher revision) should be supported if the EtherCAT master addresses them as an
older revision. The following compatibility rule of thumb is to be assumed for Beckhoff EtherCAT
Terminals/ Boxes/ EJ-modules:
device revision in the system >= device revision in the configuration
This also enables subsequent replacement of devices without changing the configuration (different
specifications are possible for drives).
Example
If an EL2521-0025-
1018
is specified in the configuration, an EL2521-0025-
1018
or higher (-
1019
, -
1020
) can
be used in practice.
Fig. 59: Name/revision of the terminal
If current ESI descriptions are available in the TwinCAT system, the last revision offered in the selection
dialog matches the Beckhoff state of production. It is recommended to use the last device revision when
creating a new configuration, if current Beckhoff devices are used in the real application. Older revisions
should only be used if older devices from stock are to be used in the application.
In this case the process image of the device is shown in the configuration tree and can be parameterised as
follows: linking with the task, CoE/DC settings, plug-in definition, startup settings, ...
