Chapter 234Note: Once you have connected your module to the host computer, power is turned on tothe module when your application program opens the module. The USB LED on the moduleturns green to indicate that power is turned on.Power is turned off to the module when your application program terminates its connectionto the module.Connecting to an Expansion HubExpansion hubs are powered by their own external power supply. The practical number ofDT9847 Series modules that you can connect to a single USB port depends on the throughputyou want to achieve.To connect multiple DT9847 Series modules to an expansion hub, do the following:1. Attach one end of the USB cable to the module and the other end of the USB cable to anexpansion hub.If you are using the DT9847-1-1, use the EP399 USB-Y cable to connect the module to twoUSB ports on the expansion hub, as shown in Figure 8.Figure 8: Attaching Multiple DT9847-1-1 Modules Using Expansion Hubs2. Connect the power supply for the expansion hub to an external power supply.3. Connect the expansion hub to the USB port on the host computer using another USBcable. Figure 9 shows how to attach DT9847-2-2 and DT9847-3-1 modules to an expansionhub.The operating system automatically detects the USB module and starts the Found New Hardwarewizard.USB CableExpansion HubsHost ComputerPower Supplyfor HubUSB-Y CableUSB-Y CableUSB CablePower Supplyfor HubDT9847-1-1ModuleDT9847-1-1Module
