MOGlabs MWM, Manual, Page: 32 / 96

24
Chapter 4. MOGWAVE
mogwave
controller to the device controller (arrow points from
MOGWave
to
Device
) or vice versa (arrow points from
Device
to
MOGWave
).
Output (V)
Shows the
PID
feedback signal
V
(
t
). Can be edited to set a fixed
output voltage, if
PID ON
is not enabled.
Setpoint λ
0
Defines the reference wavelength
λ
0
. Click on the
Set
button to use
the currently measured wavelength. The setpoint units are the currently
active
measurement
wavelength units set in the main
mogwave
window.
Gain (V/unit)
Defines the gain,
G
. The gain is in volts per measurement unit. A
typical value is 10 V
/
unit if units are nm. A negative gain can be used to
invert the sign of the output voltage.
The gain and output voltage do not change if the current measurement
units are changed in the main window of
mogwave
.
Units
The drop-down unit selector will change the measurement units on the
device. Use the main
mogwave
window to set units for
PID
using
mogwave
.
No attempt is made to adjust the setpoint value or gain for a change in
measurement units.
kp, ki, kd
Proportional, integral and differential coefficients, each limited to a
range of 0 to 1.
V
max
,
V
min
These set the upper and lower output voltage limits, and also the
integrator windup limits.
V
zero
The offset voltage; that is, the output when the laser is at the correct
wavelength,
λ
=
λ
0
. For MOGL abs
DLC
controllers, set
v
zero
= 1
.
25.
PID ON
Enables
PID
calculation and output. Disable and re-enable to reset
the
PID
controller (set the integrator to 0). Either the
mogwave
or
MWM
device
PID
controller can be activated. It can be helpful to start with
the
mogwave
controller and once that is working, copy the coefficients
across (see above), then activate the device controller, and then for highest
bandwidth, stop
mogwave
; the device-based controller can then run at full
speed.
The
mogwave
PID
controller will be stopped when the
PID
dialogue box is