RoboteQ AX2550/2850 user manual Adjust Offset and Max Speed

Closed Loop Speed Mode

6.Apply power to the Motor Power wires (thick power wires). The motor will be stopped.

7.Move the cursor of the desired motor to the right so that the motor starts rotating, and verify that a positive speed is reported. Move the cursor to the left and verify that a negative speed is reported.

8.If the tachometer or encoder polarity is the same of the applied command, then the wiring is correct.

9.If the tachometer polarity is opposite to the command polarity, then you can either reverse the motor’s wiring, or reverse the tachometer wires. If an encoder is used, you may swap its CHA and ChB outputs

10.If a tachometer is used, proceed to calibrate the Max Closed Loop speed.

11.Set the controller parameter to the desired Closed Loop Speed mode using the Roborun utility

Adjust Offset and Max Speed

For proper operation, the controller must see a 0 analog speed value (2.5V voltage on the analog input).

To adjust the 0 value when the motors are stopped, use the Roborun utility to view the analog input value while the tachometer is not turning. Move the 0 offset potentiometer until a stable 0 is read. This should be right around the potentiometer’s middle position.

The tachometer must also be calibrated so that it reports a +127 or -127 analog speed value (5V or 0V on the analog input, respectively) when the motors are running at the max- imum desired speed in either direction. Since most tachometers will generate more than +/- 2.5V, a 10kOhm potentiometer must be used to scale it’s output.

To set the potentiometer, use the Roborun utility to run the motors at the desired maxi- mum speed, while in Open Loop mode (no speed feedback). While the tachometer is spin- ning, adjust the potentiometer until the analog speed value read is reaching 126.

Note: The maximum desired speed should be lower than the maximum speed that the motors can spin at maximum power and no load. This will ensure that the controller will be able to eventually reach the desired speed under most load conditions.

Important Warning:

It is critically important that the tachometer and its wiring be extremely robust. If the tachometer reports an erroneous voltage, or no voltage at all, the controller will con- sider that the motors has not reached the desired speed value and will gradually increase the applied power to the motor to 100% with no way of stopping it until power is cut off or Emergency Stop is activated.

126 AX2500/2850 Motor Controller User’s Manual Version 1.7. February 1, 2005