How to define order of Frequency in 3-phase Voltage source block in Mat-lab simulation model?

i am using 3 phase voltage source block for Harmonic analysis but i am confused how to set frequency order in this block.

if for 60 Hz it is 1st order then for 5 Hz it is 5/60?

Please advice me this is right approach for other frequency value suppose if I am giving external disturbance at 400 Hz then what is frequency order?

Thank you in advance