ZWAVE: Channels for Fibaro FGS-224 switch module

Can anyone please advise on the OH channel names for the Fibaro FGS-224 switch module?

The module is a TWO channel lighting control switch device (with I/O labelled S1/Q1 and S2/Q2). Yet when I instantiate the thing from the OH inbox, it confusingly has THREE switch channels – namely switch_binary / switch_binary1 / switch_binary2 – and the OH documentation says the same thing.

I assume that switch_binary1 would represent S1/Q1 and switch_binary2 would represent S2/Q2 => can someone please confirm that? And if so, can someone explain what switch_binary is representing?