Using RS232 all commands work with the exception of volume ramps. The volume can only adjust 1.5db at a time and between button presses i have to remove my finger, wait three seconds then press it in order to get a response. I put the system in live view and i can see when i push and hold the volume buttons its responding properly.

I tried SR6003, SR8002, SR8003 modules and can't get the proper controls. Looking for other suggestions, everything else works fine

Thanks