Linx 4900 Operating Manual page 185

Appendix A: Installation and Setup
Step 2: Select the Encoder, Gearing, and Pitch
Factor
A particular combination of encoder and encoder drive (gearing or wheel)
gives a particular encoder pitch—the distance the product travels for each
cycle of the encoder output signal. The encoder pitch is multiplied by the
pitch factor (a whole number) to give the actual raster pitch. This should be
as close as possible to the required raster pitch.
The table below gives the encoder pitch for standard Linx encoders and
wheels. You can calculate the encoder pitch for other gearing or drives by
using the following:
Encoder Pitch (mm)
Where:
Wheel circumference = distance the product moves for one revolution
of the encoder. This may be 3.14 x roller diameter, or 3.14 x star-wheel
diameter, and so on, depending on the application.
Encoder p.p.r.
2500
5000
10000
Figure A-11 Encoder Pitch for Standard Linx Encoders and
The encoder pitch is multiplied by a whole number (or pitch factor) to give
the actual raster pitch. By selecting a suitable encoder and gearing, the
actual raster pitch can be made close to the required raster pitch.
Actual Raster Pitch (mm)
Linx 4900 Operating Manual
=
Wheel Circumference/Encoder Pitch (mm)
Your Application 500 mm
0.200
0.100
0.050
Where:
The Pitch Factor is a whole number.
166
Wheel Circumference (mm)
Encoder Pulses per Revolution
333 mm 304.8 mm
0.133 0.121
0.066 0.060
0.033 0.030
Wheels
= Encoder Pitch (mm) x Pitch Factor
68542
200 mm 50 mm
0.080 0.020
0.040 0.010
0.020 0.005
MP65492–1