simulink problem: a red wire appears rather than a simple one when tried to connect 'scope' to a simple circuit

i am doing simulation using blocks from simpower systems library, but when i tried to connect a 'scope' with a simple circuit containing just an ac power supply and diode in series and scope is connected across the ac power source. when i try to join the scope with the circuit a red wire appears rather than a usual black one and no connection is made. the same problem occurred when using a linear transformer. help plz

Answer 1

[Azzi Abdelmalek]

Interfacing the Electrical Circuit with Other Simulink Blocks