When you installed the USB signal generators, did you follow the step-by-step guide included on the drivers and instructions CD? If you just proceeded with the automatic install where it tries to locate the driver itself, it will most likely not install correctly and will not go online.
To confirm the signal generator is working, when you power on the signal generator the 5 axis lights should light up in sequence (1, 2, 3, 4, and then 5) and then all shut off. If you can confirm this then the problem most likely is the driver installation. Feel free to give us a call if you'd like someone to walk you through reinstalling the drivers for the device, or for a walkthrough guide explaining the process.