8.5.6 Methods (-7) to (0)
8.5.6.1 Homing method for increment-coded encoders
Method (-6): Movement in negative direction
Method (-7): Movement in positive direction
See Section "Distance-coded reference marks" on page 101 as well.
8.5.6.2 Method (-5): Absolute encoder
These homing methods are suitable for absolute encoders (e.g. SSI multi-turn
encoders). Homing will be carried out immediately after the mains is on. The
reference position is calculated on the basis of the encoder absolute position plus
zero offset. In the case of a SSI multi-turn encoder, homing with zero point offset = 0
gives the absolute position of the SSI encoder.
Referencing again without changing
the setting for the zero point offset does not cause a change of the position. To set
the machine reference point homing method (-12) should be used.
8.5.6.3 Method (-4) and method (-3): Not defined
8.5.6.4 Method (-2): No homing
No homing will be performed. The zero point offset is added to the current position.
When the power stage is first switched on, “Homing completed” is set as the status.
This method is suitable for absolute encoders, provided that no offset compensation
is required. For an offset compensation, please select method (-5).
8.5.6.5 Method (-1): Actual position = 0
The actual position corresponds to the zero point; it is set to 0, meaning the drive
performs an actual position reset. The zero offset will be added.
MOOG
ID
No.:
CB40859-001
Date:
02/2018
MSD Servo Drive - Device Help
194
8 Motion profile
8.5.7 Method (1) and method (2): Limit switch and zero
pulse
8.5.7.1 Method 1: Negative limit switch and zero pulse
Start movement left; at this time the hardware limit switch is inactive.
The direction of movement reverses on an active hardware limit switch edge.
First zero pulse after falling limit switch edge corresponds to zero/reference
point.
Fig. 8.45: Negative limit switch and zero pulse
8.5.7.2 Method 2: Positive limit switch and zero pulse
Start movement right; at this time the hardware limit switch is inactive.
The direction of movement reverses on an active hardware limit switch edge.
First zero pulse after falling limit switch edge corresponds to zero/reference
point.
