Instruction manual

MICRO 4000

NET Web Guide Control System

Appendix 1 / Motor Drive Calibration

Note: The PWM motor drive module is not easily accessible, however user adjustment is typically

not necessary and is not recommended.

PWM Motor Drive

The PWM motor drive converts the system command voltage into a drive voltage for the actuator

motor. The motor drive consists of a separate power supply and PWM servo amplifier. This servo

amplifier is run in voltage mode for highest response and accuracy. All adjustments are sealed

when the system is shipped and should not require adjustment. If adjustment is required, this is

easily accomplished using the following procedure:

Note: A digital voltmeter (DVM) with at least 2½ digit accuracy will be required during the

following procedure.

Adjustment Procedure:

1) Verify that the servo module is configured for voltage mode with the DIP switch set as

follows:

Switch Setting

1 ON

2 OFF

3 OFF

4 OFF

2) Put the system into Manual mode and drive the actuator to ensure that it is not at a limit.

3) Connect the DVM leads to terminals 13 and 14 (motor output).

4) Verify that the DVM reads between +1.00 and -1.00 volts. Adjust R4 (test--offset) on the

servo amplifier module if required.

5) Put the system into Automatic mode and verify that the system responds quickly to

position errors without oscillation.

6) If a whistling noise is heard from the servo amplifier module, adjust R3 (reference input

gain) CCW until it stops.

7) The other potentiometers are adjusted at the factory and do not require further

adjustment in the field. Do not attempt to adjust these potentiometers.

432 1

DIP SW .

R4R3R2R1

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PWM Servo Amplifier