SPM4650 4 pin serial rx 3pin hookup Question to gremlin

[CustomRCMods]

Hey guys, looking for some assistance here. Just went ahead and purchased a Spektrum Serial RX (4650) to drop in my new gremlin I got off @Grifflyer but I have a question on how to hook it up to the board. the gremlin has a standard 3 pin RX setup, common with most satellite and serial rx systems on the market, however my new one has a 4 pin setup. so I am curious, which wire do I drop?

here’s the SPM4650 wiring diagram:

I would assume you drop the “no connect” pad but I have literally zero clue, a complete noob to quad wiring and I need everyone’s input just to be safe. Thanks!

 

[Grifflyer]

I'm pretty sure no connect means you don't need to connect that wire to anything. My guess is they put it there so it'll be compatible with future models or something. Or some newer drones use a four pin connector to have an extra feature that isn't mandatory. Or something like that. I'm not seeing a NC port on the FC Manual so I'm guessing there isn't one.
http://download.appinthestore.com.s3.amazonaws.com/201611/EMAX Femto F3 Manual V1.1.pdf

 

[CustomRCMods]

I'm pretty sure no connect means you don't need to connect that wire to anything. My guess is they put it there so it'll be compatible with future models or something. Or some newer drones use a four pin connector to have an extra feature that isn't mandatory. Or something like that. I'm not seeing a NC port on the FC Manual so I'm guessing there isn't one.
http://download.appinthestore.com.s3.amazonaws.com/201611/EMAX Femto F3 Manual V1.1.pdf

Makes sense. I will try it out. thanks!