The AVR family is set up with a complete system of emulators, but because of the nature of the PODs of some of the emulators, they are not equipped with internal clamping diodes. ICE200 and ICE40/50 are the only emulators with clamping diodes. ICE10 and ICE30 do not contain clamping diodes. By adding external clamping diodes these emulators will get the same input as the part.
To apply a high AC voltage to an emulator can cause severe damage on the equipment and care should be taken. It is recommended to use isolation transformers on the mains and galvanic separated RS-232 communication to the PC.