Maximum Process Data Sizes
EtherCAT-capable PLCs such as the NX or NJ series have a specified maximum process data size and a maximum process data size per slave.
Although some PLCs can process up to 11,472 bytes of input and output PDOs per cycle, they are limited to 1,434 bytes of input and output per etherCAT slave (or node).
A slave is any device on the etherCAT network that is not the master. It may be a VSD, a servodrive, an etherCAT coupler such as the NX-ECC and their NX-I/Os,...
To check that a configuration does not exceed the maximum process data size,