I have Meridian 500 565 562v and all work fine with my T2. I have no experience with the 596 but if your other Meridian units are working via the T2 I would check the settings of each code in your program. Are they set to the right mode (rf or ir)? Is sustain on or off? I use mostly rf to control my system through a IRF6, all my Meridian commands go RF as the units are in another room. Did you try the codes from RTI?
Good luck, KDM ([email protected])