Focas library call eth_rdparam() not working

I'm attempting to use the eth_rdparam() FOCAS function call to obtain the Ethernet IP parameters from the controller. I have a working application that calls many other FOCAS calls that are working well. I am using the Fwlib32.dll and Fwlib64.dll's without any issues. It is returning an error code of (1) which is EW_FUNC: Error (function is not executed, or not available). And the OUT_ETHPRM return parameter is not populated with any data. I have tried using the application compiled for both x64 and x86 with no difference. I have tried both an 0MC simulator and a real 0MC machine control and neither one returns data. Any ideas?