EEROS offers predefined blocks for using EtherCAT within its control system. First download and install EEROS. You have to compile EEROS with -DUSE_ETHERCAT=TRUE when calling cmake.

...
cmake -DCMAKE_INSTALL_PREFIX=/absolute/path/to/working/directory/install-x86 -DUSE_ETHERCAT=TRUE ..
...

This will alter the timing of the executor.