T-Series/Manual control of motion products

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Manual Control

Turning the potentiometer knob will make the device move. It is not necessary to have a computer connected to use the device in manual mode. However, without a computer connected you have no means to initialize the device with a starting position. Therefore you must retract it completely after each power up in order to home the device. You will not be able to extend it fully until you have first retracted it completely to set the home position. Clockwise rotation of the knob produces positive motion (extension) and counter clockwise rotation produces negative motion (retraction).

The speed of retraction or extension will be directly related to the amount to which the knob is turned from its center detent position (turning the knob to its center position will stop the device from moving). During manual moves, the device constantly returns its position so a computer can track the position even when you are controlling the device manually. Manual control can be disabled with a mode setting.

The speed of the potentiometer-controlled manual moves is also determined by the Set Target Velocity command (#42). When the knob is fully turned to either limit, the device will move at the maximum velocity set by command #42. Any intermediate position of the knob will move the device at a velocity proportional to how far the knob has been turned. If the velocity is set to be very small, it may appear that turning the knob produces no movement. The way to verify that the actuator is moving is to connect it to a computer and monitor the replies back to the computer.

During operation if the actuator is extended or retracted against a force greater than its thrust capability the device will stall and there will be “missed steps”. This can result in an apparent malfunction in that the device believes its position to be other than it actually is and will not extend or retract the actuator past a given position. Without connecting a computer to home the device or set its position, the only solution is to retract the actuator until it activates the internal home switch, which will automatically zero the device at the home position. A problem arises if the device incorrectly believes its position to be zero since it will not retract to the home position. In this case you must disconnect and reconnect the power before manually homing the device.