I believe it was because the binary and electrical signal coming from the first user were mixed up. Generally OptiSYstem will keep track of what type of signal a port is but after a Fork component it can be anything, so OptiSystem will not stop you if you make an error. I also sped up the calculation by not converting the noise bins in the project.
Thank you Damian Marek very much ,now it work
but i want to know why not work ? and where is the error that make it not work ? and when i add another node to the file that you upload i found it not work , and can i make ring contain 60 node with 30 channel ? please help me if you can
and thank you very much for your effort
The error was at the output of the node used to calculate the BER. There are two outputs a binary signal and electrical signal. The connections going to the BER Analyzer were mixed up as the electrical signal was connected to the binary input and the binary signal was connected to the electrical input.