Mark, Have no fear, the PR4 will work fine with JMRI. ?I know because I have one, in fact my set up sound similar to yours in that I use a separate program track too and am not connected to the layout. ?And there are many talented people her3 that can offer assistance.
Common issues with the PR4 is the default power supply does not provide power to work with many sound decoders. ?It is fine with ordinary decoders from Digitrax, NCE and the factory non-sound decoders from folks such as Bachmann, Atlas and others. ?I had to upgrade my power supply to communicate to sound decoder locomotives.
To your issue, did you verify in your preferences that you are set up to talk to a PR3/4? ?Also check to verify that the loconet radio buttons are selected and that they are not set for internal.
With the loco on the test track, are you able to read all pages? ?A non-sound equipped loco should read in just a couple of minutes? ?Do you get any error messages?
If none of these items are an issue, follow what one of the previous posts and use your a DCC system to reset the loco to factory defaults with address three, then verify operation. ?If that works, then delete the loco from decoder pro, create it as a new one again, and try reading All Pages to see if you can read the decoder setting into the system. ?If you can, then simply change the address of the loco to the number you desire, and retest on your layout before doing any other programming.
George
Glikestrains