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        MIDI-OX >> Scripting Questions >> Receiving Sysex
        
(Message started by: RickRepsher on Jun 20^th, 2005, 7:01am)

Title: Receiving Sysex
Post by RickRepsher on Jun 20^th, 2005, 7:01am

I am trying to receive sysex data from a Nord Lead. So far sending messages is not a problem. This is the vba code I have been working with, but I always get a null back from the midiox instance.

' Global declaration
Dim WithEvents MWire As MIDIOXLib.MoxScript

Sub GetSysEx
Dim strMsg As String
Dim vStatus As Variant
Dim strData As String

MWire.FireMidiInput = 1

' Sysex to tell Nord to send patch data
strMsg = "F0 33 7F 09 30 04 00 F7"
MWire.SendSysExString strMsg

strMsg = MWire.GetMidiInputRaw()
vStatus = strMsg And &HF0
If vStatus = &HF0 Then
strData = MWire.GetSysExInput()
End If

If strData <> "" Then
ConvertStringToByteArray strData
Else
MsgBox "NoData!"
End If
End Sub

Title: Re: Receiving Sysex
Post by Jamie OConnell on Jun 20^th, 2005, 11:45am

I think with 'FireMidiInput' and 'WithEvents' you need to write a connection point sink routine. In any case for polling, you'll have to implement a Loop: the MIDI input data will not be immediately available, and you'll have to keep checking until it is, and keep checking until you get all of it. This is why the example code has a loop that is only terminated by the user.

Title: Re: Receiving Sysex
Post by RickRepsher on Jun 21^st, 2005, 7:05am

?????

Which example code? I have gone through the documentation looking for just such an example. Personally, I would have thought that this is a question asked all the time, and something that would have been included in the docs.

Thanks,

Rick

Title: Re: Receiving Sysex
Post by Jamie OConnell on Jun 22^nd, 2005, 3:03am

Installed with MIDI-OX are several Windows Script Host examples. They are in the WSH folder below the MIDIOX install folder (default: C:\Program Files\MIDIOX\WSH).

Here is the VB polling example:

' MIDIOX Test
option explicit

dim mox
dim str, strWrk
dim n, ii, nInst
dim bGo
dim chan, stat, dat1, dat2
dim msg, msgstr, strSysEx
dim A

' Wsh version
Str = Wscript.Name & " ver. " & Wscript.Version
MsgBox str

' Create object
Set mox = WScript.CreateObject("Midiox.MoxScript.1")

str = "MIDI-OX"
n = mox.InstanceNumber
If n > 0 Then
str = str & ":" & CStr( n )
Else
MsgBox "No Instances"
End If

str = str & " " & mox.GetAppVersion
str = str & " of " & mox.InstanceCount
MsgBox str

' *** Try out our MIDI Input loop
mox.FireMidiInput = 0

str = "Enter MIDI Input Loop?" & vbCrLf & "(Exit Script from MIDI-OX)"
If vbYes = MsgBox( str, vbYesNo + vbQuestion, "MIDI Notes" ) Then
If vbYes = MsgBox( "Divert MIDI Input?", vbYesNo + vbQuestion, "MIDI Notes" ) Then
mox.DivertMidiInput = 1
Else
mox.DivertMidiInput = 0
End If

Do While mox.ShouldExitScript = 0
' First try raw Input
msg = mox.GetMidiInputRaw()
If msg <> 0 Then
stat = msg And &h000000FF

If (stat = &hF0) Then ' SysEx, must ask for SysEx string message
strSysEx = mox.GetSysExInput()
mox.SendSysExString strSysEx
Else
msg = msg \ 256 ' pull off stat
dat1 = msg And &h0000007F
msg = msg \ 256
dat2 = msg And &h0000007F
mox.OutputMidiMsg -1, stat, dat1, dat2
End If
End If

' Now try the string format
msgStr = mox.GetMidiInput()
If msgStr <> "" Then
A = Split( msgStr, ",", -1, vbTextCompare )
stat = Int(A(2))

If (stat = &hF0) Then ' SysEx, must ask for SysEx string message
strSysEx = mox.GetSysExInput()
mox.SendSysExString strSysEx
Else
dat1 = Int(A(3))
dat2 = Int(A(4))
mox.OutputMidiMsg -1, stat, dat1, dat2
End If
End If
Loop

mox.DivertMidiInput = 0
End If

MsgBox "End Demo"

Set str = nothing
Set strWrk = nothing
Set mox = nothing

' Exit Point
'------------------------------------------

Title: Re: Receiving Sysex
Post by RickRepsher on Jun 22^nd, 2005, 6:50am

Jamie,

Ok, I didn't see the examples, only the documentation.

I still have a couple of questions.

1) Where is the loop "terminated by the user"?
2) In the following code:
strSysEx = mox.GetSysExInput()
mox.SendSysExString strSysEx
Is strSysEx the entire message, or just one byte? Are you resending the message and if so, why. Just for the example?

Thanks again

Rick

Title: Re: Receiving Sysex
Post by Jamie OConnell on Jun 22^nd, 2005, 5:16pm

1) The loop starts here:

. . .
str = "Enter MIDI Input Loop?" & vbCrLf & "(Exit Script from MIDI-OX)"
If vbYes = MsgBox( str, vbYesNo + vbQuestion, "MIDI Notes" ) Then
If vbYes = MsgBox( "Divert MIDI Input?", vbYesNo + vbQuestion, "MIDI Notes" ) Then
mox.DivertMidiInput = 1
Else
mox.DivertMidiInput = 0
End If

Do While mox.ShouldExitScript = 0
' First try raw Input
. . .

2) It is the entire message received so far. It is sent just as an example, although you might want to echo it anyway, especially if it's not something you want to handle.

Title: Re: Receiving Sysex
Post by RickRepsher on Jun 23^rd, 2005, 8:54am

I obviously still don't understand what is supposed to be happening here. If I open MidiOx in the "stand alone mode" and go to the sysex view, and enter the following string in the sysex view command window

F0 33 7F 09 31 00 00 F7

and then do a send/receive, I get data back in the display window (data that I would expect to see.)

But...

If I run the following piece of code (which is pretty much copied from the example), I get the following values as I step through the procedure.

strMsg = "0, 240, 0, 0, 0"
lngStstus = 0

After multiple loops through, there are only null values in those variables, and we have never seen an &HF0, although the "stand alone" method definitly returns one (in the first byte.)

I DO have an &HF0 in arr_strTemp(1) (zero based...)

Code:

'>>>>>>>>>>
Dim strSysEx As String
Dim strMsg As String
Dim arr_strTemp() As String

Dim lngStatus As Long

MWire.FireMidiInput = 0
MWire.DivertMidiInput = 1

strSysEx = "F0 33 7F 09 31 00 00 F7"
MWire.SendSysExString strSysEx

strSysEx = ""

Do While MWire.ShouldExitScript = 0
strMsg = MWire.GetMidiInput()
If strMsg <> "" Then
arr_strTemp = Split(strMsg, ",", -1, vbTextCompare)
lngStatus = Int(arr_strTemp(2))

If (lngStatus = &HF0) Then ' SysEx, must ask for SysEx string message
strSysEx = MWire.GetSysExInput()
End If
End If
Loop

MWire.DivertMidiInput = 0
'<<<<<<<<<<

Title: Re: Receiving Sysex
Post by Jamie OConnell on Jun 25^th, 2005, 12:33pm

I wouldn't be surprised if single-stepping through would affect the results as you're probably missing input that way. You might try the Connection point sink model, which gets triggered when there is data to collect. Again though, single-stepping through a real-time MIDI program may drop or skip data. Instead, you might want to put in some kind of TRACE or reporting statements to see what's happening. The 'sink' example is in MOXScriptDemo.vbs.

Title: Re: Receiving Sysex
Post by RickRepsher on Jun 29^th, 2005, 11:52am

Jamie,

First off, thanks for all the help so far. I have done some VBS and VBA programming, but my issues have been how I need to interact with the MIDIOX com model.

With that said... when I looked at the status message and noticed that I had an $HF0 in the second byte, I changed my code to this:

lngStatus = Int(arr_strTemp(1))

Being zero based, I got the correct status message, and I was able to grab the incoming sysex data.

Everything is smooth as silk...

Now I just need to play some more to get the feel of the rest of the model.

Thanks again.

RR