Sets any vector as the next stimulus to be output. Does not call write to hardware

def set_stim(self, signal, fs, attenuation=0):
        """Sets any vector as the next stimulus to be output. Does not call write to hardware"""

        self.tone_lock.acquire()
        self.stim = signal
        self.fs = fs
        self.atten = attenuation
        self.stim_changed = True

        self.tone_lock.release()