Can I use HI 1756WS module in a remote rack with Ethernet/IP communication?

Yes, We have tested the HI 1756 WS and 2WS modules in a remote chassis communicating through ControlNet and Ethernet back to the main chassis/PLC. 
Findings:
If you are using the older ControlNet or Ethernet modules, there was no problems found with the communications.
If you are using the newer CN2 ControlNet or EN2T Ethernet modules, then you would need to have the version 2.3 or later firmware for the HI 1756 WS or 2WS modules. 

You can find and download the latest version of firmware for the HI 1756-WS or 2WS modules in Knowledgebase 

NOTE:  You can install the HI 1756-FC and HI 1756-DF modules in a remote chassis also.