Beckhoff EL47 Series, Документация

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Commissioning
EL47xx 153 Version: 2.7
"StartTimeNextOutput" activation
The assigned process record "StartTimeNextOutput" for transfer to the EtherCAT bus can be enabled by
entering 0x1A82 in the field below, after selecting Sync Manager 2 (Fig.
Process data tab, activation of index
0x1A82, entry „StartTimeNextOutput “, top left).
Fig. 190: Process data tab, activation of index 0x1A82, entry “StartTimeNextOutput”
The StartTimeNextOutput process data is 32 bits wide. During each process data cycle the time is specified
at which the
next SYNC1 pulse and therefore the next block of sample values begins. This time is based on
the terminal-specific local distributed clock time. The EL47xx only maps the lower 32 bits of the generally 64-
bit distributed clock time.
In this way all samples can be synchronized with other time data within the EtherCAT system based on the
known oversampling factor.
Sample:
With an oversampling factor of n = 20 and a StartTimeNextOutput = 0x12345678, the next sample block of
20 samples therefore starts at the distributed clocks time of 0x123456678
hex
or 305,419,896 ns.
Fig. 191: TwinCAT tree, entry "StartTimeNextOutput"