YASKAWA SGD7S Product Manual page 208

 When Using a Linear Encoder with Multiple Origins and First Passing the Origin Posi-
tion in the Reverse Direction after Turning ON the Power Supply
The encoder's phase-C pulse is not output when the origin detection position is passed for the
first time in the reverse direction after the power supply is turned ON.
However, after the origin detection position is passed in the forward direction and the encoder's
phase-C pulse it output, it will then also be output when the origin detection point is passed in
the reverse direction.
Encoder count-up
direction
Origin 1 detection
position
Origin 2 detection
position
Origin 3 detection
position
Power ON
Phase-C pulse
output
Origin 1
The phase-C pulse is not
output.
Origin 2 Origin 3 Origin 3
6.5 Encoder Divided Pulse Output
6.5.1 Encoder Divided Pulse Output Signals
Time
6
6-13