G'day Mate,
Read your manual, it will tell you how to set it up for PCM, in the system menu Modulation Section, page 26, JR uses SPCM, & that is the way to go, you won't regret it, small extra cost for PCM, but huge advantages over PPM.
Lots of guys will tell you different, but if you go to a pattern or jet guy, he will usually only use PCM. So if it is good for them why not use it too.