[PD] Sysex out problems (linux only)

Martin Peach martin.peach at sympatico.ca
Wed Jul 8 19:05:14 CEST 2009

András Murányi wrote:
> 2009/7/8 Martin Peach <martin.peach at sympatico.ca 
> <mailto:martin.peach at sympatico.ca>>
>     András Murányi wrote:
>         Dear Sirs,
>         I just have never been successful with sysex in Pd and I'm
>         asking for your kind advice.
>         Attached is an example for a long sysex message which goes out
>         on [midiout] (linux only, afaik).
>         The problems I have:
>         - sysex gets fragmented (also when nothing is sent out meanwhile
>         by other objects). It is always properly terminated with '247'
>         but the content is often truncated. Is this a bug/feature...?
>         What is your best recommendation knowing that my patch is full
>         of sysex outs (+envelopes on some of them!)
>     in the patch you posted, the message you send to [midiout] is
>     [240,67,16,73,8,$2,19,$1,247(
>     , which Pd takes as 9 separate messages because of the comma in
>     between each item.
>     Probably [240 67 16 73 8 $2 19 $1 247( would work better.
> Dear Martin,
> that is how it goes afaik, sysex is kind of a sequence, which is comma 
> separated

Yes and no: sysex is a sequence that starts with the value 240 (hex F0) 
followed by a number of bytes, each less than 128, and ends with 247 
(hex F7). There are no commas in it unless the message contains commas. 
(If you really want to send commas you would need to specify the ASCII 
code for a comma, 44.)
As far as Pd goes, separating items in a message box makes them into 
separate messages, so it's no surprise they get sent out separately.


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