Peter Ostry

I get a SysEx stream from a synth and need to split it somehow. There are rather short blocks but I don't want all of them. In the example below I want only those blocks which have 16 as the third number:

I receive them as one stream in Max. When I monitor them in MidiMonitor I see them line by line, I think this program inserts a line break after each EOF. Is there a standard procedure in Max to split a stream and analyze each block separately? I tried a couple of more or less adventourous methods and one works almost but doesn't look solid ...

240 67 48 87 20 0 247
240 67 16 87 3 0 11 127 247
240 67 16 87 3 0 11 122 247
240 67 48 87 3 0 11 247
240 67 16 87 3 0 12 0 247
240 67 48 87 15 0 11 247
240 67 16 87 2 1 64 9 0 247

I receive them as one stream in Max. When I monitor them in MidiMonitor I see them line by line, I think this program inserts a line break after each EOF. Is there a standard procedure in Max to split a stream and analyze each block separately? I tried a couple of more or less adventourous methods and one works almost but doesn't look solid ...


how-to-break-up-a-sysex-stream

i cant quite follow what you mean by stream? do you mean it inserts a character return at the end of each line...

perhaps you could post your best attempt?

I think I delivered a confusing description.

I send parameter requests via SysEx to a Yamaha VL70-m. I get SysEx answers back. But this synth unfortunately forwards every incoming SysEx also to its output, so I receive a mix of valid answers and my own echoed requests.

Here is an original answer from the synth:

240 67 48 87 16 0 0 247 240 67 16 87 16 0 0 83 247 240 67 48 87 16 0 1

247 240 67 16 87 16 0 1 121 247 240 67 48 87 16 0 2 247 240 67 16 87 16

0 2 110 247 240 67 48 87 16 0 3 247 240 67 16 87 16 0 3 99 247 240 67 48

87 16 0 4 247 240 67 16 87 16 0 4 114 247 240 67 48 87 16 0 5 247 240 67

16 87 16 0 5 111 247 240 67 48 87 16 0 6 247 240 67 16 87 16 0 6 33 247

240 67 48 87 16 0 7 247 240 67 16 87 16 0 7 32 247

These are several short blocks in the format '240 (some data) 247'. Blocks which start with '240 67 48 ...' are my own echo. A valid answer is '240 67 16 87 (some data) 247'.

So the actual problem is to observe the stream, find out what starts with '240 67 16 87' and look what it contains until 247 (EOF). And this as long as the stream goes on.

Below is the patch with my best attempt for now. It is not functional standalone, just shows the system. My idea was to use serial switches (gates). For 240 the first gate opens. For 67 the second gate opens. Then a 48 or 16 will either close the thing or open one more gate to look for the next numnber 87. If it comes, then the following numbers until 247 are one answer I am waiting for.

It is timing sensitive, which is bad. And it has a bug because even in a valid message any number 48 will close the gates ;-) But I am not sure if I should continue to work on it. It isn't solid, I think there must be another solution.

I think I delivered a confusing description. 

The action:
I send parameter requests via SysEx to a Yamaha VL70-m. I get SysEx answers back. But this synth unfortunately forwards every incoming SysEx also to its output, so I receive a mix of valid answers and my own echoed requests.

Here is an original answer from the synth:
240 67 48 87 16 0 0 247 240 67 16 87 16 0 0 83 247 240 67 48 87 16 0 1
247 240 67 16 87 16 0 1 121 247 240 67 48 87 16 0 2 247 240 67 16 87 16
0 2 110 247 240 67 48 87 16 0 3 247 240 67 16 87 16 0 3 99 247 240 67 48
87 16 0 4 247 240 67 16 87 16 0 4 114 247 240 67 48 87 16 0 5 247 240 67
16 87 16 0 5 111 247 240 67 48 87 16 0 6 247 240 67 16 87 16 0 6 33 247
240 67 48 87 16 0 7 247 240 67 16 87 16 0 7 32 247

Two problems with this patch:
It is timing sensitive, which is bad. And it has a bug because even in a valid message any number 48 will close the gates ;-) But I am not sure if I should continue to work on it. It isn't solid, I think there must be another solution.


maybe try [match], something could work with that. also look to [zl] for list management, there's surely something there that could help---nth?

Yes but apart from one [zl] version they all work with lists, not with a stream. But, mhm, the stream isn't endless and I can control it. What about a [coll]? Shouldn't it be possible to write lines to a coll, based on block-start (240) and block-end (247)? Similar to my gate switcher above but without looking at details of each block while it is still streaming. Once the chunks are stored I have plenty of time ...

maybe try [match], something could work with that.

seejayjames wrote:
maybe try [match], something could work with that.

"match" was the magic word.
Works perfectly, thanks!


Beside this my switching patch looks like made by an electrician :-)

Nice too, yes.
Beside this my switching patch looks like made by an electrician :-)


How to break up a SysEx stream?