Beckhoff EP3356-0022, Документация

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Commissioning/Configuration
EP3356-0022 53 Version: 1.4
5.8 Distributed Clocks mode
In the Distributed Clocks mode (DC mode), the precise timestamp is recorded for each measured value and
transmitted to the controller as cyclic process data. To this end
• DC must be activated. To do this, select DC-Synchron (input based) on the "DC" tab
• The PDO x1A03 in the Process data management [
}
54] is to be activated in the SyncManager 3
"Inputs"
Fig. 35: Activation of DC and PDO timestamp in the TwinCAT System Manager
The EP3356 operates free running with a cyclic, but not equidistant measurement; the time intervals
between 2 measured values are therefore not constant. For this reason the 64-bit timestamp delivered with
the process value must be evaluated by the user.
In order to suppress falsification of the measurement results by upstream filters, both the software filter and
the averager are deactivated in this operating mode. The measurement/calculation and provision of the
measured value in the process data therefore takes place at the conversion rate corresponding to the mode:
10.5 kSps or 105.5 kSps
The minimum permissible EtherCAT cycle time is 100 µs for the EP3356 with and without DC mode.
Time stamp
See Notes on latency regarding [ } 30] the time when the actual timestamp is acquired.