THORLABS SHB025 User Manual page 10

Ø1/4" Shutters and Controller
The maximum continuous operating frequency limit is 15 Hz. The unit can operate up
to 50 Hz for a limited amount of time. After the time limit is exceeded or the modulation
frequency exceeds 50 Hz, the shutter will disable, the Status LED will turn red, and the
interlock will open. See Chapter 5 for more information on how long the unit can be run
from 16 to 50 Hz.
4.3.1. Protected Mode
When the SHB025(T) operates in Protected Mode, the device will shut down if run for
too long over 15 Hz. This is in order to protect the device from overheating. The unit
does not monitor the temperature directly, but the time limit is based on calculations
assuming no heat control at room temperature. If the user utilizes some kind of heat
mitigation system, they may set the unit to Unprotected Mode where the time limit alarm
is ignored and the device will operate continuously. Note that operating the shutter in
Unprotected Mode may damage the unit.
The following table outlines the length of time the device can be operated safely above
15 Hz.
Protected Mode Specifications
Max Operating Freq. Continuous
Burst Mode (Less than 1 minute)
4.3.2. Unprotected Mode
The SHB025(T) normally operates in Protected Mode. In this mode, the unit will disable
the blades, turn the Status LED red, and trip the interlock when the unit is run over
15 Hz and the time limit is reached (see Chapter 5 for more information). In Unprotected
Mode, the unit will not disable under those conditions.
To enter Unprotected Mode, hold both the POWER and ENABLE buttons until the
Status LED flashes amber four times. While in Unprotected Mode, the Status LED will
remain amber, so any condition that normally would be green will now be amber. To
exit Unprotected Mode, depress both buttons until the Status LED flashes green four
times. This will put the device back into Protected External Modulation Mode.
Depressing the ENABLE button while in Unprotected mode, will exit Unprotected Mode
and enter Manual Mode. The LED will turn green.
The table below summarizes the different states and how to enter them.
Current
Mode
Manual
External
Protected
External
Unprotected
Page 8
To Manual Mode
-
Press Enable button.
Press Enable button.
Chapter 4: Setup and Operation
To External
Protected Mode
Hold Enable button
for 3 seconds.
-
Hold Power and Enable
buttons for 3 seconds.
Value
15 Hz
16 – 50 Hz
To External
Unprotected Mode
Hold Power and Enable
buttons for 3 seconds.
Hold Power and Enable
buttons for 3 seconds.
-
TTN042240-D02