RoboteQ Dual Channel Digital Motor Controller AX500 - Manual (Page 68)

Closed Loop Position Mode
68 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
3. Loosen the sensor’s axle from the motor assembly.
4. Launch the Roborun utility and click on the Run tab. Click the “Start” button to
begin communication with the controller. The sensor values will be displayed in the
Ana1 and Ana2 boxes.
5. Move the sensor manually to the middle position until a value of “0” is measured
using Roborun utility
6. Verify that the motor sliders are in the “0” (Stop) position. Since the desired posi-
tion is 0 and the measured position is 0, the controller will not attempt to move the
motors. The Power graph on the PC must be 0.
7. Apply power to the Motor Power input (Vmot terminals). The motor will be stopped.
8. With a hand ready to disconnect the Motor Power cable or ready to press the “Pro-
gram” and “Set” buttons at the same time (Emergency Stop), SLOWLY move the
sensor off the center position and observe the motor’s direction of rotation.
9. If the motor turns in the direction in which the sensor was moved, the polarity is
correct. The sensor axle may be tighten to the motor assembly.
10. If the motor turns in the direction away from the sensor, then the polarity is
reversed. The wire polarity on the motors should be exchanged. If using a potenti-
ometer as sensor, the GND and +5V wires on the potentiometer may be swapped
instead.
11. Move the sensor back to the center point to stop the motor. Cut the power if con-
trol is lost.
12. If the polarity was wrong, invert it and repeat steps 8 to 11.
13. Tighten the sensor.
Important Safety Warning
Never apply a command that is lower than the sensor’s minimum output value or
higher than the sensor’s maximum output value as the motor would turn forever try-
ing to reach a position it cannot. For example, if the max position of a potentiometer
is 4.5V, which is a position value of 114, a destination command of 115 cannot be
reached and the motor will not stop.
Encoder Error Detection and Protection
The AX500 contains an Encoder detection and protection mechanism that will cause the
controller to halt if no motion is detected on either Encoder while a power level of 25% or
higher is applied to the motor. If such an error occurs, the controller will halt permanently
until its power is cycled or it is reset.
Adding Safety Limit Switches
The Position mode depends on the position sensor providing accurate position information.
If the potentiometer is damaged or one of its wire is cut, the motors may spin continuously