[Al Skierkiewicz]

General,
What is critical to the discussion is the actual signals we are discussing. In standard RC PWM the pulses vary from 1msec to 2msec but do not repeat for up to 30 msec (repetition rate) That makes the RC PWM about 50 Hz rep rate. On the website you and I have been referencing, the PWM signal for the LMD is required to be at least 1kHz rep rate and have no pause between signals. That is why the interface is reguired. Although PWM signals can be decoded by filtering as Ed has pointed out, most of these devices use a clock circuit and compare the incoming pusle against the clock to obtain the best accuracy. The comparison will start at the beginning of the pulse and count clock cycles until the pulse ends. A 10kHz clock would then transistion 10 cycles for a 1 msec pulse and 15 cycles for 1.5msec pulse width. The clock comparator is actually much higher in frequency but you get the idea.
The max currents you refer to is the actual maximum current that can be drawn by the input when the input signal is 12 volts peak to peak. It is a measurement that indicates how many devices can be connected across the same logic output. If for instance the logic feeding the LMD is only capable of sourcing 20 micoramps then that device can only feed two LMD devices reliably.
The RC and Edu controllers both output RC PWM standards and that is why they talk directly to servos. Your reference page does hint at the repsonse of a servo to incoming PWM. The waveforms you refer to are the limits of the RC PWM. A 1.5msec pulse is interpreted by the servo as zero, a 1 msec as full reverse and a 2 msec is full forward.