Tuning Your System; Proportional Gain (Stability); Integral Gain (Stability); Position Error Gain (Follower Mode) - Seco DS9000 Installation & Operation Manual

PARAMETERS PRESET RATIO 2
SET-UP
PARAMETERS
TUNING
PARAMETERS
Parameters ACE1 and dEC1 are not displayed when operating the DS9000 as a Follower
controller. These parameters apply when using the DS9000 as a setpoint controller. Refer to
section 3.0 for information on these parameters.
5.0

TUNING YOUR SYSTEM

The DS9000 utilizes a digital version of a classic proportional and integral (PI) error amplifier with
reference feed forward. An error signal is generated by comparing the speed reference entered by the
operator to the actual speed of the controlled motor, measured by the pulse generator.
5.1

PROPORTIONAL GAIN (STABILITY)

The proportional gain of the system is accessible by changing the parameter PE. The factory setting of
PE, which should be acceptable for most applications is 200. Range of adjustment is 50 to 2000, with
higher values representing a lower gain. As with all closed-loop systems, increasing the proportional
gain will make the system more responsive to speed changes, causing the system to correct for error
more rapidly. Too much proportional gain can cause system instability. A lower setting of PE will
increase gain and make the system more responsive. If erratic or unstable operation is noted when the
speed is changed, decrease the system gain by increasing the value of PE.
5.2

INTEGRAL GAIN (STABILITY)

The integral gain of the system is accessible by changing the parameter IE. The factory setting of IE,
which should be acceptable for most applications is 300. Range of adjustment is 50 to 2000, with
higher values representing a lower gain. The integral gain of the system allows the speed to be
corrected to the set value without overshoot. Too little integral gain will cause droopy operation, with
the actual speed never quite reaching, or very slow to reach, a higher set speed. To correct for this
type of performance, increase the integral gain by decreasing the value of IE. Too much integral gain
can cause actual motor speed to overshoot when speed reference is rapidly increased. This undesirable
characteristic can be eliminated by decreasing the integral gain by increasing the value of IE.
5.3

POSITION ERROR GAIN (FOLLOWER MODE)

When used in the follower mode, the DS9000 provides a "Position Lock" between the master motor's
shaft and the controlled motor's shaft, assuming 1:1 ratio is set. With other that 1:1 following ratios,
the master and follower motor shafts keep a constant relative speed. To perform this function, the
DS9000 actually counts pulses from the master motor's pulse generator and maintains the same (or
proportional) number of pulses from the following motor. The time taken to count and correct, thus
reducing position error to zero is set by adjusting the position error. The factory setting of POSE,
which should be acceptable for most applications is 5 to 300, with higher values representing less
gain. Sluggish response may be improved by decreasing the value of POSE. If unstable operation is
noted, the value of POSE should be increased.
(PS2)
PRESET RATIO 3
PRESET RATIO 4
MINIMUM SPEED
MAXIMUM SPEED
FEEDBACK RESOLUTION (CONTROLLED MOTOR) – FEd0
FEEDBACK RESOLUTION (MASTER REFERENCE) – FEd1
SCALE FACTOR (CONTROLLED MOTOR) – SCF0
SCALE FACTOR (REFERENCE SIGNAL) – SCF1
SCALE FACTOR DECIMAL PINT (CONTROLLED MOTOR) – SCd0
SCALE FACTOR DECIMAL POINT (REFERENCE SIGNAL) SCd1
PROPORTIONAL ERROR GAIN (PE)
INTEGRAL ERROR GAIN (IE)
POSITION ERROR GAIN (POSE)
(PS3)
(PS4)
(LO)
(HI)
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