Futaba,
I have been setting up a plane on PCM with my Futaba 9C and digital Hitec servos, while at the same time, I have also been flying another plane with Hitec digitals, but this plane is on PPM. (I have two different receivers, both on channel 21, but one is PCM, and the other is PPM.)
I was about to fly my PPM plane when I accidentally turned on my Tx while it was still on PCM mode, from setting up the other (PCM) plane. My servos started glitching like crazy back and forth for a second, before I realized that I was still on PCM mode, and needed to change to PPM mode. Could this have possibly hurt anything? I switched back over to PPM and did a range check, and everything seems fine, but would like your advice first. Thanks for any help.