How to use digital/trigger ports#
Every Presto comes with 4 digital outputs and 4 digital inputs.
pulsed sequence can be triggered either from an internal trigger (by default) or from one
of the 4 digital inputs. An instance of
TriggerSource class is passed as an argument to
Pulsed.run() function. For example, a sequence can be triggered by a signal on digital
pls.run(period=1.0, repeat_count=1, num_averages=1, trigger=TriggerSource.DigitalIn2)
Digital triggers/markers can be output at defined times during a pulsed sequence using
Pulsed.output_digital_marker(). For example, the following code will output five markers of
increasing length every 5 μs on digital output port 1:
length_list = np.linspace(0.5e-6, 2.5e-6, 5) port = 1 # int or list of ints in [1,4] T = 0.0 for length in length_list: pls.output_digital_marker(T, length, port) T += 5e-6
Digital markers have an amplitude of 3.3 V (see the signal captured by the oscilloscope connected to digital output port 1 below) and an output impedance of 50 Ω.