Abacus software is designed to automatically look to the local area network whether any Abacus units are present. If so, they will be displayed in the GUI and users may choose to connect to them. This is achieved by sending a broadcast packet at port number 1092. The packet will be sent every 30 seconds. The broadcast can be stopped by unchecking the "broadcast" check box at File --> Connect --> Searching for Controllers.
Note that for users with software release before 5.20, these broadcasts can not be stopped. They have to upgrade their software to 5.20 or above.