Yaskawa Sigma-5 User Manual: Design and Maintenance - Rotary Motors - Analog Voltage and Pulse Train Reference - Manual (Page 334)

9 Fully-closed Loop Control
9.1.6 Precautions When Using an External Incremental Encoder by Magnescale
9-8
When Passing 1st Zero Point in Reverse Direction and Returning after Power ON
After the power is turned on, the phase-C pulse (CN1-19, CN1-20) is not output when the external encoder
moves reverse and its head first passes the phase-C detection position. The phase-C pulse is output for the first
time when the external encoder moves forward and its head passes the detection position. After the detection
head of the encoder first passes the detection position in the forward direction, the phase-C pulse is output
when the head passes the position regardless of the direction of the encoder’s movement.
When Using an External Encoder with Multiple Zero Points and Passing 1st Zero Point in
Forward Direction and Returning after Power ON
When using an external encoder with multiple zero points, the same logic as that explained earlier for an
encoder with only one zero point applies to each zero point.
See When Passing 1st Zero Point in Forward Direction and Returning after Power ON.
The phase-C pulse is not output
when passing the detection position
in reverse direction first. The phase-C pulse is also output when passing this point in reverse,
because the SERVOPACK has recorded the position where the phase-C pulse was
originally output when first passing the position in the forward direction.
Scale count-up direction
Phase-C detection position
Power ON
Time
Phase-C pulse output
Rotation
Even after zero point 1 has first been passed
in the forward direction, the phase-C pulse is not
output here because zero point 2 is passed
in reverse direction. The phase-C pulse is also output when passing this point
in reverse, because the SERVOPACK has recorded
the position where the phase-C pulse was originally output
when first passing the position in the forward direction.
Scale count-up direction
Power ON
Time
Phase-C pulse output
Zero point 1 Zero point 1 Zero point 2 Zero point 2
Rotation