Enabling Distributed Clocks - Beckhoff CX8110 Manual

6.6.1

Enabling distributed clocks

This chapter explains how to enable distributed clocks (DC) in the slave interface of the CX8110. To this
end, the CX8110 is scanned in TwinCAT, and the slave interface and the lower master of the CX8110 are
created.
Proceed as follows:
1. In the tree view on the left, click on EtherCAT slave.
2. Click on the EtherCAT Slave tab
3. Select the Enable Synchronization option.
ð You have successfully enabled distributed clocks (DC) if the variables DcToTcTimeOffset, DcTimeDiff
and Dc State were created under InfoData. From now on you can measure the time difference between
the master and slave clock with the variable DcToTcTimeOffset. You can determine when the CX8110 is
synchronized by reading the value of the DcTimeDiff variable. A control configuration can be regarded as
optimal with a task time of 1 ms and a DcTimeDiff of less than 10 ns. A DcTimeDiff of less than 100 ns is
regarded as adequate.
In the next step you can configure the master of the CX8110.
CX8110 Version: 1.4
Configuration
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