JBL TUNE600BTNC Quick Start Manual

LinX Series Linear Motor - User Guide14 D-000168 Rev 02 ANCA MotionLinear Encoder4.5The linear encoder is used to provide position feedback to the servo drive to allow for accurate control of the LinXmotor. The type of encoder used depends greatly on the application; factors such as the required precision,operating environment and servo drive signaling requirements need to be taken into account. As the LinX motordoes not have any backlash, it is recommended that any position feedback system chosen also does not containbacklash. The most commonly used encoders consist of an encoded surface, either solid rail or adhesive strip,mounted parallel to the shaft and a sensor read head mounted to the forcer.NOTE: To maximise performance, the encoder should be placed as close as possible to the motor. If theremust be separation, maximising the stiffness to minimise deflection is desired.Resolution4.5.1Encoder resolution has a large impact on the precision, accuracy and smoothness of the LinX cylindrical motorsystem. The positional accuracy of the system can never be greater than the position feedback supplied by theencoder. Additionally, the response speed of the encoder must be taken into account when operating at theapplications top speed. Finally, the servo drive’s maximum encoder bandwidth must also be considered. Consultyour servo drive manual on supported encoder signal types and bandwidths.Magnetic Encoders4.5.2Due to the highly magnetic nature of the shaft, care must be taken when installing a magnetic encoder. It ispossible that the shaft will affect the strip or read head resulting in inaccuracies or damage. Therefore, it isnecessary to ensure the encoder components are a sufficient distance away from the shaft. Installing the encoderat a minimum distance of 150mm from the surface of the shaft is recommended.Sensors4.6End Stop Sensors4.6.1End stop sensors, also known as limit switches, are used to prevent motor travel in the case of incorrectbehaviour. In the event that the motor passes a defined maximum physical position, the end stop sensors will betriggered which can stop and/or disable the motor, minimizing potential damage. In addition to end stop sensors,it is recommended to incorporate end stop bumpers to absorb and stop the movement in the case of over travel.Home Sensor4.6.2When an incremental encoder is used, the servo drive will not know the absolute position of the motor relative tothe machine. To establish the absolute position, it is necessary to move the motor to a known ‘home’ location,often referred to as ‘homing’. The servo drive can be informed that it has reached the ‘home’ location in manyways, the most common being via a proximity switch at one end of travel and/or an index (marker) pulse.Temperature Sensor4.6.3The LinX cylindrical linear motor contains a KTY84/130 temperature sensor. The sensor increases in resistanceas the motor winding temperature increases. When this temperature sensor is employed, the trip temperatureshould be set no higher than 120°C, and the accuracy of the circuitry involved should be no worse than +/-8°Cincluding the sensor accuracy.Note that, although the sensor is located in the center of the motor, it is possible in certain use cases for anuneven temperature distribution within the forcer to result in the sensor reporting a lower value than the maximumtemperature within the motor. Therefore, it is recommended that the current limits in section 5.1 are obeyedthrough use of I2R overload protection within the servo drive. Both the AMD2000 and AMD5x servo drive seriesoffer I2R overload protection functionality.