Hello,
As far as loops are concerned there are few links i am posting that might help u. Generally The Loop Control allows you to set the number of times the signal propagates in the components that are connected between the Loop Control input and output ports. Use the Loop Control to calculate the system performance based on the number of fibers.
To connect the Loop Control, perform the following procedure.
From the Component Library, select Default > Tools Library.
Drag the Loop Control to the Main layout.
Connect the output port of the WDM Mux 8×1 to the first Loop Control input port.
Connect the first Loop Control output port to the Optical Fiber input port.
Connect the output port of the second EDFA Ideal (connected to the Optical Fiber) to the Loop Control input port.
Here is the complete link
Hope this helps you
Thanks