dhenry:
Yes, but a servo control signal is a specifically defined subset of a typical true PWM signal,
So you confirmed what we have been saying: the servo signal is necessarily PWM and a PWM signal isn't necessarily a servo signal.
Agreement is good.
frame rate (20-25msec) is 'standarized' amoung devices designed to receive 'servo commands'.
I think you have plenty counter examples of that in this thread.
I'm not so sure of that. I've read several opinions and statements here, but I've yet to see a link to a datasheet for a ESC that was designed to handle both standard servo signals and some propritary non standard PWM switching and duty cycle control signal. Not saying one doesn't exist, but it would certainly not be a typical common ESC. I would like to read more details on real products offered, as there are likely to be applications where such higher performance control would be useful or required.