QuantumDrive-4000 Manual 25
91-0027 Rev. E
Copyright © Nutfield Technology, Inc.
6/2010
10.2 Potentiometers (Main Board)
10.2.1 DC Offset (Command Offset) (R139)
DC or Command Offset
(R139)
is the pot that changes the center position of the
galvanometer rotor by adding a small DC offset into the command input signal. This
pot is often used to adjust the center position of scan angle.
10.2.2 PD Gain (R11)
PD Gain (R11) is used to adjust the gain of the Galvanometer’s Position Detector before
it enters the control loop.
10.2.3 Slew Rate Limiter (R14)
When enabled via jumper (J4) adjusts a threshold at which a step-command is
transformed into a ramp-command. This is done so that the Galvanometer and mirror
remain under control during large-field instantaneous jumps.
10.2.4 Command Attenuator (R66)
Command Attenuator (R66) attenuates the command signal prior to entering the servo
loop.
10.3 Match Tuning of X and Y Galvanometers
Match tuning of X and Y galvanometers refers to tuning each servo to have the same
response time to a given command input. If a set of X and Y servo drivers in a 2 axis
head are not match tuned, a command that would draw a 45-degree line may result in a
line that looks “bowed.” This would be caused by one servo responding faster than the
other.
10.4 Vector Tuning
Vector tuning refers to tuning a servo drive to respond to a variety of different size step
commands where the galvanometer is continuously moving. Laser marking is a good
example of a vector application.
