TL708EX TekLink 8-Port Hub. The TL708EX Hub is housed in a standard 19 inch rackmount frame. (See Figure 23.) The hub allows you to expand your system to accommodate up to seven additional TLA7000 Series mainframes, con?gured as expansion mainframes (48 modules total). When you power on the TL708EX TekLink 8-Port Hub, the hub scans the eight TekLink connectors sequentially. The hub then assigns master mainframe status to the mainframe that is connected to the lowest number hub connector used (the #1 connector is used for the master mainframe). The next-highest numbered hub connector that you use is assigned as the ?rst expansion mainframe. Any remaining expansion mainframes that are connected to the hub are assigned second, third, etc. using this hierarchy.