On the DX product line the ISO function on a beltpac is the intended button to press to isolate the talk from the wired intercom attached to the base while talking to other wireless beltpacs. The front panel headset port on the base has the ability to hear ISO if it is selected on the front panel.

There is an ISO-Split jumper located inside of the DX-210 base to engage the ISO-Split function. When engaged the ISO function will not occur on both channels. It will occur only on the channel that is selected prior to engaging the ISO button.