Featuring unique structure and diversified varieties, slub yarns are widely used in textile and apparel production. To make the production management easy, a network-based production monitoring system is developed by introducing computer technology and serial communication technology to the existing microprocessor control. All the slub yarn production machines are connected via RS-422 network and thus can be monitored by a central computer. Production parameters of all the machines in the workshop can be set, modified and retrieved on the central computer.