I know I'm dragging up an old post here, but I hate when people ask questions and don't provide solutions. I stumbled across this old post of mine when looking for something else and figured I shouldn't be that bad person and answer my own question for anyone else looking in the future.
Preamble done.
Bottom line, you can do it, easily. This is the module I settled on:
Diewu Ethercat Slave Io Module 8 Channels 16 Input 16 Output Npn Input Module 100mbps With Dual Rj45 Port Ab Phase Encoder - Network Switches - AliExpress
You should be able to just throw the below code into your ethercat *.xml file (taking care to ensure that your slave id, pid and pdo's have the right lables) and then you'll have the pins available to you, in my case listed as: lcec.0.4.in-XX or lcec.0.4.out-XX
I hope that helps someone else.
