I am using HyperLynx 8.1.1 to try to simulate a differential pair from an ADC to an fpga. When I select the model for the receiver and attempt to simulate, I get an error window stating "Error creating simulation model: failed modeling IBIS differential R_series at pin U103.N2. Check that both pins share the same reference designator and that the pin names match the IBIS file's [Diff Pin] keyword." I have tried to modify the IBIS pin mapping but I am obviousley doing it wrong. I have tried to find a similar example to mine, but have not been able to. I am specifically trying to use a Virtex6 LVDS_25_DT_N signal in the IBIS. Does anyone have any suggestions that may help me.