You’re absolutely correct in this case.
The Nano Dimmer and Nano Switch have to external switch ports and both can react the same or be modified to directly control other devices directly through group association which depends on your configuration. Although S2 external switch port has an interesting setting for only 1 way triggers which is a slight difference in use between S1 and S2.
I would just suggest connecting the switch to S1 and COM only if using one switch.
@dan-dotson Most users will just use S1 to COM or S2 to COM connections for control over the Nano device. (Doesn’t specifically matter which S1 or S2 port you use, by default they both will control the load).
The schematic shows 2 switch connections, both are completely optional for this unit. If only one switch is to be wired, its easier to explain that S1 to COM only need to be connected while you don’t need any connection over S2.
Perhaps it would be easier to see the schematic as such by removing the second switch:
Some additional information asides from using parameter settings to set it back into auto detect, you can do this manually:
forcing the Nano Dimmer to enter external switch detection mode:
- Tap the Nano Dimmer button 4x times within 1-2 seconds which will force Nano Dimmer to enter External Switch detection mode.
- Flip your external switch once, then wait at a minimum 10 seconds before you flip the switch again.
- Now test your external switch.
Alternatively, you can use Z-Wave Tweaker to force the external switch mode
Configure the external switch mode for S1. //Edited, Thanks @Bill_Crowder
Parameter 120 [1 byte size]
(0) Unknown Mode
(1) 2-state switch mode
(2) Momentary push button Mode
(3) 3-way switch mode
(4) Enter auto switch detection mode
If using S1 to COM connection:
Parameter 120 [1 byte] = 3
@Navat604 - Z-Wave Tweaker is a powerful tool, i think it should be a mandatory SmartApp 
