ETS-Lindgren 2188 Turntable - Manual (Page 25)

Model 2188 Turntable
©ETS-Lindgren—January, 2006
Rev. B—P#399771
25
the ENTER key. To set the clockwise rotational limit for the
turntable, press the UP/CW key under LIMIT. The indicator light
above this key will light. Set the limit by pressing the INCRM and
DECRM keys under LIMIT until the desired limit is shown on the
display. Press the ENTER key.
WARNING: Ensure the current travel limit settings will not cause
damage to existing cables and equipment located underneath the
turntable.
Should continuous operation be desired, the Model 2090 series
controller permits easy configuration to this type of operation from
the front panel or through the IEEE-488 interface bus. Refer to the
positioning controller manual for more information. The limit pins
should also be removed form the turntable top to allow for
continuous operation.
5.3. Turntable Encoder Calibration
Parameter
C, which calibrates the encoder counts to the rotation of
the turntable, must be set to the value 3600. Parameter
C Refers to
the encoder calibration parameter. This setting is used to convert
the encoder count values returned from a motor base into the
corresponding centimeter or degree position reading. For
turntables, this represents the number of encoder counts per
revolution. The setting for the Model 2188 turntable series is 3600.
If the given value does not appear to work correctly, the encoder
calibration value can be determined using the following procedure:
1. Set the encoder calibration value to 3600.
2. Ensure that the turntable is positioned to allow more than a full
revolution of travel in the clockwise direction and use the STEP
keys to run the turntable clockwise a few degrees to remove any
play in the table.
3. Mark the current location of the turntable against the ground ring
(masking tape works well for marking), and set the current
position reading to 000.0.
4. Using the STEP keys, rotate the turntable clockwise until it is
again aligned with the mark on the ground ring. For best
results, the last motion should always be in the clockwise
direction to ensure that any play in the gearing between the
motor and encoder is accounted for.