How to determine Servomotor Attributes

I am modeling a velocity control connected to a servomotor. I have been able to find all but 2 attributes for the servomotor.

The first is "Fixed Losses Independent of Torque and Speed". From the Brushless DC Motor SimElectronics example, this is defined as Vcc*I0 where Vcc is the nominal supply voltage and I0 is the no-load DC current drawn from the driver power supply. How do you determine I0 and under what conditions. I assume zero torque but what speed (rated?).

The second is "Supply Series Resistance". Under what conditions is this determined?

Any help is greatly appreciated.