NRPN Not visible

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mlostek
mlostek's picture
NRPN Not visible

Hi, 

first of all thank you for this cool tool :)

 

I am having a small issue, i am sending an NRPN command that is composed of 3 MIDI CC messages 

 

B9 99 64 || B9 98 100 || B9 06 127 (decimal values)

 

But the only thing i see in the log is the first two messages (MSB and LSB). Is there some setting in the Midi Tools to enable NRPN receiving? I mean the third message (06, the actual value) is not received / shown.

 

Thanks

M++

Mark van den Berg
Mark van den Berg's picture

What OS are you on?
When I make the Windows edition of MIDI Tools send these three messages (from the "(N)RPN messages" window) to a virtual MIDI device (loopMIDI) and loop them back to MIDI Tools itself, all three show up.
I'm not near a Mac at the moment, so conceivably the macOS edition of MIDI Tools (which is relatively new) could contain some kind of bug in this respect, but I doubt that as well.

As far as I know, if all the checkboxes at the top of the "Input messages" window are checked, absolutely all messages are shown that are being received.
And no difference is made between different types of CC messages (which is what your individual messages are).
So if the third message isn't shown, it simply hasn't been received, either because it hasn't been sent or because it has been suppressed along the way.
Your third message is an MSB data message, so maybe it is being withheld because the sending device (or some in-between agent, i.e. a MIDI port) requires an LSB data byte to be sent as well. Or maybe the data byte should be sent in an LSB message?

You might try using MIDI Tools' "(N)RPN messages" window to debug this problem: it has been designed exactly for this type of problem.

Hope this helps,
Mark

mlostek
mlostek's picture

Hi,

thanks. I will check with a LSB data byte message too.

I am on OSX. It seems that there is no "(N)RPN messages" window on OSX. Am i right?

mlostek
mlostek's picture

Ah, sorry. Just found it, there is no button for it, its only in the menu. 

Thanks, i will get back as soon as i have results

mlostek
mlostek's picture

But one general question.

Did i get the principle of NRPN correct, i mean sending MSB, LSB, DATA LSB (, DATA MSB) one after each other? 

Mark van den Berg
Mark van den Berg's picture

A book on MIDI I have gives an example with the order NRPN MSB (99), NRPN LSB (98), followed by a sequence of Data Entry MSB (6) + Data Entry LSB (38) pairs.
It makes sense that you have to send the Data Entry LSB after the Data Entry MSB message: the LSB then provides a "finetuning" of the MSB. Under this protocol it should even be possible to send a sequence of only LSB messages once the MSB has been established.
Are there any devices requiring the Data Entry LSB before the Data Entry MSB? It wouldn't really surprise me, though I can't remember ever encountering this.
I don't know if the official MIDI specification says anything about this.