Component menu by selecting Analog Primitives then Waveform Sources then Pulse
Source. From the dialog box for the Pulse Source, select SQUARE from the box on the
right-hand side. Set the required amplitude and frequency of the square wave signal by
changing the amplitude, duration and repetition period of the pulse sequence in the model
description area of the square wave signal source. For a 1 kHz square signal, set the pulse
parameters as follows: P1=0, P2=0, P3=500U, P4=500U and P5=1M.
Set the signal amplitude in fields VZERO to -0.2(V) and VONE to 0.2(V). Note that this
corresponds to a magnitude of Vp-p = 0.4V.