Triggering - THORLABS KBD101 User Manual

Brushless DC Servo Driver K-Cube

6.3.6 Triggering

Fig. 6.9 Triggering Tab
Triggering Introduction
The K-Cube motor controllers have 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.
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