Distributed Clocks mode (EL3356-0010, EL3356-0090 only)

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 0x1A03 in the Process data management is to be activated in the SyncManager 3 “Inputs”

Distributed Clocks mode (EL3356-0010, EL3356-0090 only) 1: — Activation of DC and PDO timestamp in the TwinCAT System Manager

The EL3356-0010 and EL3356-0090 operate free running with a cyclic, but not equidistant measurement; the time intervals between two 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:

EL3356: 10.5 kSps
EL3356-0010, EL3356-0090: 10.5 or 105.5 kSps

The minimum permissible EtherCAT cycle time with and without DC mode is 100 µs for the EL3356-0010 and 150 µs for the EL3356-0090.

Time stamp

See Notes on latency regarding the time when the actual timestamp is acquired.