RE: Re: Midisport and sysex
RE: Re: Midisport and sysex
- Subject: RE: Re: Midisport and sysex
- From: "Peter Karlsson" <email@hidden>
- Date: Wed, 22 Dec 2004 20:18:09 +0100
I think I got it now. My app starts without sending any request at all to
the MIDISport. The app just runs and when I click the button that send a
request to the device, the app waits 1 second for an answer. If the app
don't get an answer it sends the request again. A variable is keeping track
of the number of retrys. This variable is set to 4 at the moment. And I
have not had any problems with the MIDISport so far. But it's to early to
say. It seems to work. The great thing is that I don't have to know what
devices is connected to my app. I just use the app as a user would do.
To explain it in a simple way. I use the timeout feature to fix 2 things.
The timeout and the MIDISport data toggle problem. And I wish my english
was a little better :-)
Peter
Ursprungligt meddelande
> I'm afraid I'm not quite sure what you're asking. The reply message
confirms
> the device heard the request message, which I take to mean communications
is
> open in both directions and the device is listening. In my code, I don't
> proceed until I've confirmed this. In addition, the reply contains some
> information you may or may not care about. Over time, the user may unplug
> the device, so you can't assume communications will stay open forever, but
> this is a good start.
>
> circa 12/22/04 9:40 AM, "Peter Karlsson" <email@hidden> wrote:
>
> > The USB data toggle accurs only on input you said. Does that mean that
I must
> > get a device to answer my request? I can't just send a request?
> >
> >> The USB data toggle issue I know about occurs only on input, not
output, and
> >> I have only seen it on one model which has firmware similar but not
identical
> >> to the model you have. You've asked for recommendations for MIDI
interfaces
> >> because the several you've tried don't work. All this suggests to me
we don't
> >> yet know the origin of the problem. Even if the problem is in the
interface
> >> or the driver, that means there are many broken systems out there,
including
> >> ones whose firmware cannot easily be updated, and your app will be less
> >> viable unless you find a way to support them. My goal here is to avoid
> >> pointing fingers while helping enable you to move forward; this is why
I am
> >> still asking questions.
> >>
> >> One harmless transaction which many MIDI devices support is the
identity
> >> request/reply transaction.
> >>
> >> http://www.google.com/search?q=MIDI+identity+request
> >>
> >> In summary, you send a message and hope a device responds with a
little bit
> >> of information about itself. I frankly can't tell you how likely a
given
> >> synth or other module is to support this transaction, but it seems a
library
> >> editor is likely to be talking to the sort of device which would
support this
> >> transaction.
> >>
> >> What I have done in the past is send out an identity request message,
wait a
> >> second for a reply, and, if I haven't received one, send out another
request
> >> and wait another second for a reply. Depending on your situation, you
may
> >> want to loop more than twice. Having received a reply, I assume the
device is
> >> ready to communicate more generally. This is the sort of reassurance I
like
> >> to have before I proceed with such communications regardless of any
other
> >> issue, but then I am known to be especially fussy about such things.
:-)
> >>
> >>> The problem here is that I don't know what synthesizer or other
module is
> >>> connected to my app. Because this is a multi device library editor.
So I
> >>> can't just send out a sysex message for some device and hope for an
answer
> >>> that will fix the MIDISport problem. A workaround is a rather
complicated
> >>> thing in my case.
> >>>
> >>> So I suggest that you keep on working for a MIDISport fix. After all,
it's a
> >>> MIDISport problem. And I feel sorry for all costumers all around the
world
> >>> that keeps buying MIDISports without knowing that it's not working
properly,
> >>> like myself. At least they have the right to know about the problems
before
> >>> they buy but that is not the case here.
> >>>
> >>> The nice thing is that a app don't have to know what MIDI interface is
> >>> connected. But if we must make workarounds for a particular interface
the
> >>> whole idea is gone. I can be wrong but I think we must solve the
problem
> >>> where it begins.
> >>>
> >>>> We of course cannot promise a fix for this problem in any particular
> >>>> time-frame. I am not even sure what the problem is yet. When you say
your
> >>>> attempted work-around has failed, what are the details? I had
suggested
> >>>> that you attempt to perform some harmless transaction with your
synth once
> >>>> and then try a second time if you receive no response after a
second. Does
> >>>> your synth support such a transaction? If so, what happened?
> >>>>
> >>>>> Now I have this MIDISport 4x4 and this will not work either. And I
can't
> >>>>> get my workaround to fix the sysex problem. Open question to
M-Audio. What
> >>>>> is M-AUDIO going to do about it?
>
> --
>
> Pete Gontier
> http://www.m-audio.com/
>
>
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