George,
Looking through the post the type of command station is not mentioned. What command stations are you
using? and what is your configuration.
PR3 and programming track
Command Station DSC50,100,240 programming track and PR3
Being that it is a club you guys should have a backup system. Take this time to create a backup system and kill two bird with one stone. Use a window system. The reason is diversity. Digitrax PR3 is a window system device and its Soundloader is windows only program. Loading Soundloader will give you the basic configuration needed to test and operate the PR3. If there's ever a problem in the future you can plug the PR3 to the window system and verify its good, connect it back to the Mac and start your fault isolation knowing that the problem is not in the cable, power supply or PR3.
Frustration has the tendency to make us irrational. It causes us to yell out one four letter word and overlook the operative word "FREE". It happens to all of us. The key is perseverance.
306 means JMRI sent a message to the command station and it did not respond. If the Error initializing Decoder Pro window did not pop up when you started DecoderPro then your com port is good.
Look in Edit, Preference, Connection and see what System manufacture, System connection and command station type JMRI is looking for.
If all is right look in the Defaults and make sure all the radio buttons are selected for Loconet
Ichi
