Block multiple identical sysex?

Hi gurbz ,

Assuming you are talking about those katana sysex messages, then here is one technique:

IF M0 == F0 41 00 00 # roland sysex
  IF M7 == 12 60 00 # KATANA

    # detect dupe message within last 100ms
    # If is a dupe, set L83 to 1
    ASS L83 = 0 # assume not a dupe

    # compare message with previous
    # previous data of katana message is in
    # L80-2 (address+value)
    IF MA == L80 L81 L82
      # use a timer variable to limit
      # the compare window
      IF T0 < 64
        ASS L83 = 1
      END
    END

    # always remember the last message (address+val)
    # into L80-2
    ASS L80 = M0A M0B M0C

    IF L83 == 0
      # we have a new message, so you put your code
      # that processes the message inside this IF/END
      ...
    END

    # dupe, message should be blocked
    IF L83 == 1
      XX = XX +B
    END
   
  END
END

In later versions of Stream Byter you can block and terminate the script, but for the version in MDP, it is safer to set that L84 flag and put in conditionals since a XX = XX +B (block) removes the event but the script will continue which could have unexpected results if you were examining the message further down that has been blocked.

It would also be possible to write code that retained/compared any message whatsoever, but this might add a bit of overhead as each message needs to be compared and maintained with loops.

Regards, Nic.

I’m not totally right but 64 is too small.
I changed it to IF T0 < 1000 and that works OK!
Thanks Nic!

Hi gurbz ,

I had assumed the dupe messages were being sent at the same time (or close together) so that is why I made the timeout small. You don't have to have a timeout at all of course, but you figured it all out for your own setup in any case.

BTW - IF T0 < 1000 will be a 4 second timeout (since that's a hex number).

I checked out the MD post - thanks!

Regards, Nic.

You might be OK removing that IF T0 clause entirely in your case?