THORLABS K-Cube Piezo Controller User Manual page 54

Chapter 6
MMI Display
In certain applications, it may be necessary to adjust the brightness of the LED display
on the top of the unit. The brightness is set in the Display Intensity parameter, as a
value from 0 (Off) to 100 (brightest). The display can be turned off completely by
entering a setting of zero, however, pressing the MENU button on the top panel will
temporarily illuminate the display at its lowest brightness setting to allow adjustments.
When the display returns to its default position display mode, it will turn off again.
Furthermore, 'Burn In' of the display can occur if it remains static for a long time. To
prevent this, the display is automatically dimmed after the time interval specified in the
Display Timeout parameter has elapsed. The time interval is specified in minutes in
the range 1 to 480. The dim level is set in the Dimmed Intensity parameter, as a
percentage of full brightness from 0 (Off) to 10 (brightest) but is also limited by the
Display Intensity parameter if this is lower. These settings are only visible and active
if the Dim device display on inactivity box is checked.
Triggering Introduction
The K-Cube piezo controller has two bidirectional trigger ports (TRIG1 and TRIG2)
that can be used to read an external logic signal or output a logic level to control
external equipment. Either of them can be independently configured as an input or an
output and the active logic state can be selected High or Low to suit the requirements
of the application. Electrically the ports output 5 Volt logic signals and are designed
to be driven from a 5 Volt logic.
When the port is used in the input mode, the logic levels are TTL compatible, i.e. a
voltage level less than 0.8 Volt will be recognised as a logic LOW and a level greater
than 2.4 Volt as a logic HIGH. The input contains a weak pull-up, so the state of the input
with nothing connected will default to a logic HIGH. The weak pull-up feature allows a
passive device, such as a mechanical switch to be connected directly to the input.
When the port is used as an output it provides a push-pull drive of 5 Volts, with the
maximum current limited to approximately 8 mA. The current limit prevents damage
when the output is accidentally shorted to ground or driven to the opposite logic state
by external circuity.
Warning: do not drive the TRIG ports from any voltage source that can produce an
output in excess of the normal 0 to 5 Volt logic level range. In any case the voltage at
the TRIG ports must be limited to -0.25 to +5.25 Volts.
Trigger Config
When configured as an input, the TRIG ports can be used as a general purpose digital
input, or for triggering a relative, absolute or home move. When used for triggering a
move, the port is edge sensitive. In other words, it has to see a transition from the
inactive to the active logic state (Low->High or High->Low) for the trigger input to be
recognized. For the same reason a sustained logic level will not trigger repeated
54 HA0365T Rev Dk Jan 2017