Outline Of Function - Omron NX701-1 User Manual

Additional Information
If you use an OMRON G5-series Linear Motor Type Servomotor/Servo Drive with built-in Ether-
CAT communications, you can set the absolute encoder home position. If you use a Linear
Motor Type, observe the following points when reading this section.
• A Linear Motor Type does not use an encoder. It uses an external scale, which functions in a
similar way.
• "Absolute encoder" in this section means "absolute external scale" for a Linear Motor Type.
• An absolute external scale does not have the rotation data of an absolute encoder. Any rota-
tion data setting procedures that are required for an absolute encoder and not required. A bat-
tery to back up the rotation data is also not required.
• Refer to the G5-series AC Servomotors/Servo Drives with Built-in EtherCAT Communications
Linear Motor Type User's Manual (Cat. No. I577) for the specifications of Linear Motor Type.
8-4-1

Outline of Function

To define home with an absolute encoder system, the absolute encoder offset compensation is per-
formed when the MC_Power (Power Servo) instruction is executed.
For a CPU Unit with unit version 1.10 or later, home is also defined when EtherCAT process data com-
munications change from a non-established to an established state, in addition to the previously men-
tioned step.
Home can also be defined by performing a homing operation in the same way as for an incremental
encoder. After home is defined, the difference between the command position and the absolute value
data read from absolute encoder is saved to the battery-backup memory in the CPU Unit as the abso-
lute encoder home offset.
The absolute encoder home offset is also set to the difference (i.e., the offset) between the command
position after defining home and the absolute value when the MC_Home or MC_HomeWithParameter
instruction is executed. The MC Function Module automatically saves the absolute encoder home off-
set to the battery-backup memory in the CPU Unit. You do not have to perform a save operation from
the Sysmac Studio.
Precautions for Correct Use Precautions for Correct Use
• When absolute encoders are used, the absolute encoder home offset for each axis is saved to
the battery-backup memory along with the axis number. The saved offset is lost if the axis
number is changed. If you change the axis number, set the Homing Settings again.
• If you replace the CPU Unit or the Battery for the CPU Unit, make sure home is defined and
back up the absolute encoder home offsets before you start the replacement procedure.
• You can restore the backed up data after finishing the replacement procedure to use the home
that was previously defined.
• Use the Sysmac Studio to back up and restore the data.
Refer to the Sysmac Studio Version 1 Operation Manual (Cat. No. W504) for specific proce-
dures.
NJ/NX-series CPU Unit Motion Control User's Manual (W507)
8 Homing
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