CONTREX ML-Drive - Manual (Page 2)

SCALING
After completing the required wiring of the ML-Drive, follow the procedure below to scale the ML-Drive for Master
format RPM operation. Complete this procedure before scaling the ML-Drive for engineering units.
1. While pressing the “CLEAR” and “7” keys on the keypad, apply AC power to the ML-Drive
(loads factory default parameters).
2. Enter the pulses-per-revolution of the feedback sensor into CP-31. The keypad sequence for a 60 tooth gear
sensor is “Code Select”, “3”, “1”, “Enter”, “6”, “0”, “Enter”.
3. Enter the maximum system operating RPM into CP-20, and CP-34. If the feedback sensor is not directly
connected to the motor shaft, enter the maximum feedback sensor shaft RPM.
4. Press the “SETPOINT” key and enter ½ of the RPM entered in Step 3.
5. Press the RUN pushbutton.
6. Verify the motor direction is forward (exchange A1 and A2 if not forward).
7. Press the “TACH” key. Verify an RPM reading appropriate to the motor setpoint speed.
8. Press the R-Stop pushbutton.
The ML-Drive is now properly scaled in RPMs. If engineering unit setpoints and/or displays other than RPMs are
desired, refer to Chapter 3 of the “ML-Drive User Manual” .
TUNING
If the drive system acts unstable or sluggish in response to setpoint or load changes, it may be necessary to tune the
ML-Drive. Follow the procedure below to improve system performance:
1. Set CP-66 (Integral) and CP-67 (Derivative) to zero.
2. Reduce CP-65 (Gain) until the system goes unstable (erratic). Stability can be tested by moving between two
wide spread setpoint values. When instability is reached, increase the CP-65 number slightly until the system
stabilizes (larger values reduce the system gain).
3. Using only Gain, the system setpoint value may never be reached due to system losses. Reduce CP-66 (Integral)
until the system becomes unstable, then increase the Integral number slightly until the system stabilizes and the
desired setpoint value is reached.
4. Derivative (CP-67) is only required if the system is too sluggish after setting the Gain and Integral terms. The
Derivative value, like Gain, should be reduced to the point of instability, then increased slightly until the system
regains stability.
C C C C C
O N T R E X , I N C . O N T R E X , I N C . O N T R E X , I N C . O N T R E X , I N C . O N T R E X , I N C .
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