Galil DMC-4040, User Manual

Page: 276 / 284

the user in the range of 2
5
through 2
12
points per sinusoidal cycle via AF command. See the AF command in the
command reference for more informaiton.
The unique position within one cycle can be read using the following equation:




=
a
b 1 -
n
V
V
tan
360
2
Fine
The overall position can be determined using:
Fine 2 les Coarse_cyc Position
n
+ ⋅ =
Where:
n is the number of bits of resolution that were used in the conversion.
Coarse_cycles is the whole number of cycles counted.
Fine is the interpolated position within one cycle.
Vb and Va are the two signals as indicated in Figure A7-23: Sinusoidal Encoder Signals.
For example, if the encoder cycle is 40 microns, AF10 results in 2 10 =1024 counts per cycle, or a resolution of 39
nanometers per count.
A7 – ICM-42100 (-I100)
•
267 DMC-40x0 User Manual