A terminal mode of at least a part of terminals in a centralized control area and terminals in a distributed control area is set to a time division control mode for performing communication in a time division manner. The safety mechanisms include a breakable link, liner socks, belt guards and a rapid-release connector. An alignment mark constituted by a bump formed simultaneously with the bumps for contact is added to the thin film with bumps. A table top has a table top surface configured to fit on the folding wagon frame.