avr as540 220V To 110V and 50HZ To 60hz

Firstly, there are two metal plates here. If you need 110V, you should short-circuit these two metal plates. If you need 220V, you should remove the short-circuit connector.
Next, for 60Hz, you should toggle the dip switch downwards. There are indications here (toggle downwards for 60Hz, upwards for 50Hz).
For 120V, you can set it the same way as 110V.