A portable bookshelf apparatus that is collapsible and can be easily moved and placed in a new location with minimum effort. When network communications are passed via the cascade connection an indication is included of whether it originated from a port that is part of a trunk and thereby port-mismatch errors can be avoided. The individual modules can typically be connected by means of simple fiber splices. The electronics unit and the light-emitting device are integrated into the shift operating unit. The paddle assembly is in mechanical communication with the generator.