No, the data channels are a separate chip set, so they can be run independently of what is happening with the isoPower converter. On side 1 the data channels will still draw quiescent current and drive data to side 2. On side 2, if power is available from a source other than Viso, it will continue to operate normally. If side 2 is powered by Viso, it will shut down when Viso is disabled, but side 1 power must be switched separately if you need low power from the data section. A pass transistor controlled from the Pdis signal should be used to turn power off to Vdd1.