I am trying to control an adcom gfr-700 via an RTI t4 coupled with an RP-6. I have the settings at 9600 baud, 8 data, no parity, 1 stop bit, flow control:hardware but when I am entering the command into the Rs232 on the button edit I have no clue what format to use. Has anyone used RS232 control for adcom with RTI who can show me an example of a working command. I cant seem to get any commands to work at all. Does it require null modem? the protocol says it does not. The way it is described in the manual the proper command format would be

{D0x28} for a volume up command, but it does nothing. If you have programmed adcom via rs232 on an rti system can you please give me some insight? Thank you in advance for all your help.