Problem: Bar code labels or photoelectric mechanical flag seals are attached to the pallets of hanger conveyors that are used to transport small lots of CRTs or monitors for TVs and PCs in the processing and assembly lines. Because the hangers sway, the reading depth changes and the labels or seals sometimes cannot be read, causing the line to stop. The number of models being produced has increased due to diverse user needs and the appearance of LCD and plasma TVs. This has created the need for frequent line changes, and the resulting complex processes make control by a host computer extremely difficult. Mount a Data Carrier (ID Tag) onto the hanger pallet carrying the product. Write the data to distinguish models in bits (for example, 0000 for product A, 0001 for product B, and 0010 for product C, allowing 16 models to be distinguished with four bits). Install a system with Intelligent Flags and a PLC at each process. When the work at each process ends, write the process end flag data onto the Data Carrier. Use a "1" flag for ending, and a "0" flag for not ending (for example, for four processes, use 0001 for the end of process 1, 0011 for the end of process 2, and 0111 for the end of process 3. These will enable process progress management).