Hypertherm HTA Rev 6.00 Install Guide - Manual (Page 70)

58 Installation & Setup Guide
Integral Gain
Integral Gain improves the positioning accuracy of the control loop. Integral Gain can be used to
compensate for static friction or gravity. Excessive Integral Gain can result in system instability.
For most shape cutting machines, this parameter should be set to Zero (0).
Derivative Gain
Derivative Gain helps to dampen out sudden changes in velocity. The higher the derivative gain, the
slower the response time to the control loop. For most velocity loop drives, this parameter will be set
to Zero (0).
Feedforward Gain
Feedforward Gain can be used to drive the following error to zero during machine motion. In all
digital control loops there is a finite amount of error that is introduced by the velocity command.
Increasing Feedforward Gain can reduce this introduced error.
Velocity Gain
When using a current loop amplifier, the internal velocity loop in the control can be used to provide
dampening without an external tachometer.
Using the internal velocity loop with a current loop amplifier can result in higher static stiffness,
smoother machine motion, and less overshoot.
Servo Error Tolerance
Allows the user to program the amount of servo loop Following Error to be allowed prior to display an
error message. The parameter is limited to a maximum value of five inches.
Encoder Counts per inch
Enter a value that is the number of encoder edges per inch of machine travel. It is possible to enter
fractional encoder units and the control will keep track of these fractions automatically. Encoder
Counts per inch are equal to the resolution of the encoder, multiplied by the encoder revolutions per
inch or mm (based on the machine drive gearing).
For example: The resolution of a 4X - 1000 line encoder counts both edges ( lines ) of channel A and
channel B to equal 4 counts per line multiplied by the 1000 lines per revolution would equal 4000
counts per revolution. If the encoder revolutions per inch to travel are 1:1, we would have 4000
encoder counts per inch of travel.
Encoder Counts/ Inch = 4 Counts/ Line x 1000 Lines/ Rev x 1 Rev/ Inch = 4000
Fault Ramp Time
This parameter sets the motion deceleration time after a fault occurs. At the end of “Fault Ramp
Time, The drives will be disabled.