Ring barrier controllers (RBC) are used to create signal groups. The *.RBC file contains all the standard parameters of a signal controller with some advanced options. It is best practice to import an *.RBC signal file directly from Synchro as a baseline. It is recommended to check the signal timing in the Vissim RBC file against Synchro as values are sometimes not imported correctly. Save the *.RBC file in the same folder as the Vissim *.INPX file for Vissim to read it during model development and simulation.