Rockwell Automation 1391 USER MNL/DIGITAL AC SERVO DR - Manual (Page 36)

Chapter 5
Inputs, Outputs and Switch Settings
5-7
When using the A Quad B option with Allen-Bradley IMC motion
controllers, the AMP parameters will be set according to the line count
selected. In general, one parameter must be justified when using this
device.
Important: For all IMC classic products (IMC 110, 12x) the normal line
counts per cycle of the encoder must be divided by two since the drive will
see two markers per cycle.
Example (using an IMC 12x Controller)
With switch S1 set to 1024 lines per revolution (S1-2 OFF, S1-1 ON), the
lines per cycle of the position feedback device (located in the Feedback
Parameters File) must be 2048.
1024 x 4 = 4096 / 2 = 2048
Lines/Revolution 2 Markers/Revolution
(Quadrature)