So in each bin, there is a number of encoder pulses that were captured during training.
Getting technical here, but no :-)
The worm and gearbox can both have quite large errors,
and have no "datums" to determine position,
so the only known constant for a Meade is the encoder on the motor.
The absolute definition of a "Meade" PEC bin is thus based on a set no of encoder pulses.
The Meade LX200GPS has 51200 "pulses" per rev of the worm
( 256 vane encoder and 50:1 gearbox = 50 * 256 * 4 )
sooo, one PEC bin = 51200/200 = 256 quadrature pulses EXACTLY.
The PEC data is actually stored as a speed multiplier "factor"
ie when a PEC bin trips, the system uses PECSpeed = Sidereal speed * PEC factor
The problem comes in how to calculate the PEC "factor.
Most other mounts can read positions dozens of times per second
so can use actual time taken vs theoretical time taken in order to get a percentage.
Because Meades read rates are sooooo glacial, you cannot get accurate trip times
or real bin trip positions, so they sum/count the time the slew keys were down
and use that to "assume" an error and reverse engineer a rate.
As such, the initial calcs are a bit woofy,
Then during playback, the real bin transitions can also be off by up to half a bin
so affects the time * rate corrections sent
Its all very rubbery, and guiding then hides the residuals ( as always )
Andrew Johansen Melbourne Australia