New to Sysex and not sure I am using app correctly

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FrankM's picture
New to Sysex and not sure I am using app correctly


Referencing Page 2 of VT-4_MIDI_Imple_eng02_W.pdf I have used MIDI Tools to create a config to deisable Monitor Mode. I also created another to change USB Mixing to 0:

Monitor mode: F0 41 01 00 00 00 51H 12 10 00 00 05 00

USB Mixing: F0 41 01 00 00 00 51H 12 10 00 00 07 00

The above were copied to the clipboard from the app.

However, playing each separately appears to have no effect.

Am I missing something?

Any suggestions would be gratly appreciated.



Mark van den Berg
Mark van den Berg's picture

Several points:

  • The third byte of your messages is "01". However, the MIDI implementation document of the VT-4 states that "10H" is the default. The correct value depends on the "Device ID" (or whatever it's called exactly) of the receiving device: if these values don't match, your VT-4 won't react at all. If the VT-4 functions like most other Roland devices I've seen, the default "10H" will be shown on the device as "17", i.e. the decimal representation of 16(=10H) + 1.
  • Both your messages contain "51H", which should be "51". (This is just a typo, but still...)
  • Any SysEx message needs to be terminated by "F7".
  • Any Roland DT1 message needs a checksum byte immediately before "F7".

MIDI Tools has a dialog box in which you can construct full Roland DT1 messages; most importantly, the dialog box automatically calculates the correct checksum.
You can open this dialog box from the "MIDI System Exclusive messages" window via Edit -> "Insert Roland" or via the "R" toolbutton.
In this dialog box, you need to set the value for "Device" to the decimal value shown on the device, i.e. probably 1 higher than the internal value. So for the VT-4's default "10H" you need to set "Device" to "17".
For "Model" the VT-4 needs "00 00 00 51".
Address/size length = "4"
Command = DT1
Address = e.g. "10 00 00 05" (Monitor Mode)
Data = e.g. "00"
For the above values, the dialog box generates the following message:
F0 41 10 00 00 00 51 12 10 00 00 05 00 6B F7

Hope this helps,