5
ADJUST TEMPERATURE
SETPOINT
1. Press to access the TC Control Screen.
2. Press the blue Setpoint temperature value
and turn the adjustment knob to change it. The
instrument will beep when set.
The TC Control Screen is also the location of the PID
control parameters and IntelliTune (intelligent autotune)
characterization scan. The PID values are manually editable
or can be adjusted automatically via IntelliTune.
ENABLE TC CURRENT
Press the
TC ENABLE
button on the front panel. There is no
delay before the button illuminates and the current flows to
the thermoelectric.
When current to the thermoelectric is enabled, this light will be
illuminated blue.
Using a 10 kΩ test load, temperature will not stabilize. Current
will drive to the positive limit if setpoint temperature is below
25ºC and to the negative limit if setpoint is above 25ºC.
SET THE LIMITS – LD
1. Press to access the Laser Diode Driver
Control Screen.
2. Access the LD Limit Screen, press the blue
text to make it editable, then use the adjustment
knob to configure the limits as required.
If current reaches the set limit, output current will
remain at the limit. Output will not be disabled if
the limit is reached.
CHOOSE LD CONTROL MODE
On the LD Control Screen, choose either
Constant Current or Constant Power mode.
Pressing the text toggles the selection.
It is not editable while LD current is enabled.
CONSTANT CURRENT MODE
Constant Current (CC) mode maintains a constant current
through the laser. The setpoint corresponds to the current
through the laser.
CONSTANT POWER MODE
Constant Power (CP) mode maintains a constant current
through the monitor photodiode, corresponding to a constant
power output. If CP mode is chosen, additional parameters
must be set on the Photodiode Screen. The test load will not
work in CP mode.
1. Press to access the Photodiode Screen.
2. Press the blue text next to "PD Biasing" to
toggle whether the bias voltage for the photodiode is
enabled or disabled.
3. Press the blue text next to "PD Range" until the value
matches the appropriate current range for the photodiode.
The available options are 500 μA, 5 mA, and 10 mA.
4. If the transfer function relating photodiode current to
optical power is known, this value can be entered using
the "Transfer Function" setting. Units are W/mA.
SET LASER TYPE
Access the LD Control Screen. Edit the laser
type by pressing the blue text to toggle between
Types A/B and Type C lasers.
Ty p e A L a s e r D i o d e
Ty p e B L a s e r D i o d e
Ty p e C L a s e r D i o d e
Common
Cathode
Laser Diode Anode &
Photodiode Cathode Common
Isolated Photodiode
Short the
Laser Diode Anode
to Photodiode Cathode
Common
Anode
Laser Diode Cathode &
Photodiode Anode Common
Figure 4. Laser Type Diagrams
NOTE: Type A/B lasers use a separate connection on the rear
panel from Type C lasers. Ensure that the proper rear panel
connection is made in addition to selecting the proper type on
the LD Control Screen.
SET LASER SETPOINT
Also from the LD Control Screen, edit the laser current setpoint
by pressing the blue text and turning the adjustment knob.
ENABLE LASER CURRENT
Press the
LDD ENABLE
button on the front panel. By
default, there is a 2 second delay (user-adjustable via remote
commands) between the time the button is pushed and current
being supplied to the load.
When laser current is enabled, this light will be illuminated
solid red.
MONITOR ALL I/V OUTPUTS
Press to access the Dual Monitor Screen.
From here, both the TC and LD output
parameters are displayed. Parameters are not
editable from this screen.
SHUTDOWN THE INSTRUMENT
If either of the Enable buttons are illuminated, current is still
flowing to the load. Before shutting down, the current needs
to be turned off.
1.
Press the Enable button. The button light will turn off and
current to the test load will stop.
2. On the back panel, press the power switch to the
O
position. The instrument will shut down.
