I'm not sure what you're asking.
The PR3 has it's own, built-in USB interface, so no, you don't have to purchase "another USB2.0 device" in order to use it.
But I don't understand what you mean by "daisy chain the Digitrax PR3 Programmer via your DCC system to your PC".
That sounds backwards to me. The PR3 allows communication between your PC and your DCC system or programming track.
But the "via your DCC system to your PC" part of your question makes it sound like you want to use your DCC system to communicate between the PR3 and the PC? What do you hope to accomplish by that?
Steve
Is the problem that you've maxed out all the USB ports on your PC, so you've got no place to plug the PR3 into?
I'd agree with David that your use of the PR3 is likely to be very occasional, and only to download files. So, if nothing else, just unplug the layout and plug in the PR3, and then reverse the procedure when you want to go back to running trains. USB ports are pretty forgiving.
It takes an iron man to play with a toy iron horse.
alloboard wrote:If your existing Digitrax DCC system is already connected to your PC, is there a way one can daisy chain the Digitrax PR3 Programmer via your DCC system to your PCwithout having to purchase another USB2.0 device?
THe PR3 has both USB and Loconet Connections, the only needed add-ons would be the power supply (around $8), and possibally a loconet cable, if you don't have an extra one floating around, it comes with a USB cable.
Also the PR3 does not need to be connected to the command station to program locos, it has self contained programming track outputs.
If you are out of USB ports, you can pick up a USB hub for about $20 that will add four or five extra connections.