Does anyone have any knowledge about 4 wire smoke detectors? The ones I just saw are wired with 2c w g NM.From the label on the smoke it looks like a 120 hot/neutral, a blue interconnect and a orange wire labeled (-). I have never seen this type of setup before. Can I make this work for standard 3 wire smokes?

The smokes were made by Square D, if this helps.

TIA,
Jim