Parker 406LXR Series, Product Manual

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Parker Hannifin Corporation
EMN Automation - Parker
Irwin, Pennsylvania
24
406LXR Series Product Manual Chapter 3 - Setup and Usage
Setting Home Sensor
The 406LXR is equipped with a “ home ” position reference sensor. This hall effect sensor in located
in the limit/home module. This sensor is typically used in conjunction with the encoder “ Z ” marker
(refer to “ Z ” channel reference below). If the unit is equipped with this option it will be set at the “ Z ”
channel location. If another home location is desired the home target can be adjusted by loosening
the set screw on the target and sliding it along the track. Note: If the home sensor is used without
“ Z ” channel, repeatability is reduced to +/ - 10 microns.
Z Channel Position Reference
The Z channel is an output on the encoder. Many servo controllers support this input. The Z channel
on the 406LXR is located in one of three positions, (positive end, mid travel, or negative end). The
location depends on how the unit was ordered (See Chapter 2, Part Number Identification ). The Z
channel is a unidirectional device. This means that the final homing direction must occur in one
direction. The 406LXR is set that the final home direction is to be toward the positive side of the table
(See Chapter 2, Dimensional Drawing , for positive direction definition). The repeatability of the Z
channel is equal to +/ - 2 resolution counts of the encoder (except for 0.1 µm scales which have a
repeatability of +/ - 1 µm). Thus the repeatability of the “ Z ” channel equals:
Encoder Resolution Z Channel Repeatability
5 µm +/ - 10 µm
1 µm +/ - 2 µm
0.5 µm +/ - 1 µm
0.1 µm +/ - 1 µm
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
positioner 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.
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
errors and possible run away conditions.