LX80L Series Product Manual
34
Parker Hannifin Corporation
EMN Automation - Parker
Irwin, Pennsylvania
Setting Home Sensor
The LX80L is equipped with a “home” position reference sensor when purchased with Home configuration
option H3. The home sensor is located on the same PCB as the limit sensors and the target is located
between the limit targets. If another home location is desired other than what is set at the factory, the
home target can be adjusted by using the same procedure as the Limit triggers, see
Adjusting the Limit
Trigger Position
section, page 23. The Home sensor location is aligned with the encoder Z-channel.
Changing the Home position from the factory setting will disable the Z-channel thus reducing the Home
repeatability. Note that the encoder Z-channel can not be adjusted.
Z Channel Position Reference
The Z-channel is an output on the encoder. Many servo controllers support this input. The Z-channel on
the LX80L is near the end of travel towards the positive end of the table (See Chapter 2,
Dimensional
Drawing
, for positive direction definition)
.
The Z-channel is a unidirectional device. This means that the
final homing direction must occur in one direction. The LX80L is set that the final home direction is to be
toward the positive end of the table. The repeatability of the Z-channel is equal to the repeatability of the
table. Thus the repeatability of the Z-channel equals:
Encoder Resolution
Z Channel Repeatability
5 micron
+/- 10 micron
1 micron
+/- 2 micron
0.5 micron
+/- 1 micron
0.1 micron
+/- 0.4 micron
NOTE
: Home repeatability is also very dependent on controller input speed and homing algorithms.
The above repeatability does not include possible controller tolerance. Additionally, to achieve the
highest repeatability the final homing speed must be slow. Slower final speed usually results in
higher repeatability.
NOTE
:
The Z-channel output is only one resolution count wide. Thus the on-time may be very brief.
Due to this some controllers may have difficulty reading the signal. If you are experiencing the posi-
tioner not finding the Z-channel during homing, try reducing final homing speed; also refer to your
controller manual for frequency rates of the Z-channel input.
NOTE
: The Z-channel is located approximately 10mm from the positive end of travel. This is a
fixed location.
Grounding / Shielding
All cables are shielded. These shields are to be grounded to a good earth ground. Failure to ground
shields properly may cause electrical noise problems. These noise problems may result in positioning er-
rors and possible run away conditions.
The motor cable has an area of the shield exposed to allow a grounding path from shield to drive ground.
The Hall/Encoder and Limit/Home cables have the shield carried through the connector hood that is in turn
grounded through the drive. LX80L purchased with ViX drives as part of the configurable part number
come equipped with p-clips designed for the small OD of the motor cable to allow the cable shield to be
grounded to the ViX ground.
Summary of Contents for LX80L
Page 56: ......
