I want to append an ac source signal with an arbitrary signal generated from waveform generator(33120) and amplified using Vref option in ac source 61604 such that at the appending point there are no disturbances. Basically, I want the ac source signal (say of 230V) to come for 10 seconds and then an arbitrary signal should come after that with no transients in between. Can any one suggest me some idea to do that.