Simscape™ block diagrams use physical signals instead of regular Simulink® signals. Therefore, you need converter blocks to connect Simscape diagrams to Simulink sources and scopes.
Use the Simulink-PS Converter block to connect Simulink sources or other Simulink blocks to the inputs of a Physical Network diagram. You can also use it to specify the input signal units. For more information, see the Simulink-PS Converter block reference page.
Use the PS-Simulink Converter block to connect outputs of a Physical Network diagram to Simulink scopes or other Simulink blocks. You can also use it to specify the desired output signal units. For more information, see the PS-Simulink Converter block reference page.
For a detailed example of using converter blocks to connect Simscape diagrams to Simulink sources and scopes, see Creating and Simulating a Simple Model.