Lens Control Modes. AMX AXB-CAM

Introduction

Lens Control Modes

The Servomotor and Motor modes are two Analog Voltage Control methods available on the

PosiTrack units.

Servomotor Mode

This method is generally used in broadcast or videoconference-style lenses. The voltage range used for servomotor style lenses is +2.5 to +7.5 VDC. These lenses can be controlled in two different modes: positional mode and speed mode.

! Positional mode is the most common Servomotor mode. When voltage changes, the lens moves and remains still until the voltage changes. For example, if a lens receives a voltage of +3 VDC, the lens moves to the corresponding position and stays there as long as the voltage remains at +3 VDC. The movement speed of the lens motor is a function of the PosiTrack unit’s analog output. The lens servomotor receives the preset voltage when a preset is recalled in the positional mode.

! Speed mode moves the lens when the voltage deviates from the center point of its range.

The farther the voltage moves away from the center point of reference, the faster the lens motor moves. The lens must have POT outputs when recalling a preset in this mode,. The outputs pass to the PosiTrack unit, and when the received voltage level matches the level stored in the preset, the voltage returns to zero. Servomotor mode lenses not having POT outputs do not have preset recall capability.

Motor Mode

Motor mode is used when the lens requires the motors be directly driven from an external source.

The standard voltage ranges are

± 6 VDC or ± 12 VDC with a center (no motion) of 0 VDC. Unlike servomotor lenses, these only operate in speed mode.

The lens moves in relation to the voltage offset from zero. The farther the voltage moves away from the center point, the faster the lens motor moves. The lens must have POT outputs when recalling a preset in this mode, these outputs are then passed to the PosiTrack unit. When the received voltage level matches the level stored in the preset, the voltage returns to zero. Motor mode lenses not having POT outputs do not have preset recall capability.

Pan and Tilt Control

Presets and travel limit stops are based on encoder counts from a home position index, located at the center of each axis’ range of motion. The SETUP button, on the rear of the unit, allows you to run a series of pre-set movements designed to test a sample of the PosiTrack unit‘s field of motion.

The system does 10-degree tests of motion for both directions of pan and tilt, and then returns to its

center position. Refer to Configuration Settings section on page 5 for more information on the

SETUP button.

AXB-PT10/30 PosiTrack Camera Controllers 3