Not sure what you are getting at there, Dennis. The FC-7 does NOT use a MIDI port (it has its own dedicated nine-pin DIN input). And, I don't THINK I can remember a Roland arranger with the ability to turn Melody Intell on/off with a MIDI command (can you?).
About the only way I think you could do this at the moment is to set up UPG pairs, with one with Mel/Intel on, and one with off, and then use UPG up/down as a way to enable/disable it.
Yeah I know that,the FC7 has its own port(I did own a G70 and an FC7, remember

)
And no, not via a MIDI command, but the FCB allows you to program Sysex messages to each of the pedals instead

I am sure I read
somewhere the Roland sysex data to do this, of course maybe I am remembering incorrectly??? But I am pretty sure there were the strings somewhere...I could not be bothered as I owned the FC7
Dennis