Beckhoff EL6692 Documentation page 117

Operation mode
The EL6692-0002 can be operated with or without distributed clocks support. If no DC synchronization is
required DC support can be switched off and the terminal can be operated in FreeRun mode. In this case the
corresponding diagnostic process data are irrelevant. If DC support is desired, it must be activated on the
primary and secondary side; see the fig. Mode switching. The operating mode "DC synchronous" only affects
the operation of the EL6692 with distributed clocks synchronization.
Fig. 148: Mode switching
Support for distributed clocks with EL6692 in Beckhoff TwinCAT
Full support for distributed clocks synchronization with the EL6692 is provided from TwinCAT ver-
sion 2.10 build 1340 or higher. Previous versions are limited to process data exchange.
Data transfer through the EL6692
Transporting the configured process data from one EtherCAT side to the other takes a certain amount of
time, depending on the number of bytes. The data transfer is free-running and therefore not synchronized
with one of the two EtherCAT sides. As a typical sample, measurement of an EL6692 with FW01 shows the
following values:
Fig. 149: Typical throughput time measurement for a EL6692 (FW01) - Beckhoff reserves the right to
modifications without notification.
The user is responsible for ensuring (via the diagnostic variables available for the EL6692 or a higher-level
handshake) that data overload of the EL6692 is avoided with small EtherCAT cycle times (i.e. the quantity of
data supplied to the device must not exceed the quantity the device can transport to the other side).
Link with process data SyncMode
The "SyncMode" status process data has 2 bits. IEC61131-PLC contains no data type that can be linked with
this process data directly. This data was nevertheless chosen deliberately for reasons of data transfer
efficiency.
An input variable of the type Byte must be defined in the task/program for linking; see the fig. Definition of
byte process data.
Fig. 150: Byte process data definition
EL6692 Version: 3.2
Commissioning
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