Message
RE: Re: bcr2000 failed firmware 1-10 upgrade with mac osx, "noOS&qu
2013-11-14 by <markwinvdb@...>
as USB-to-MIDI devices too:
This is how my BCR behaves when I send SysEx messages from the "MIDI System messages" window in BC Manager or MIDI Tools (under Windows 7 SP1 64-bit, with Behringer USB MIDI driver 1.0.10):
Input messages in Operating Mode U-3:
A SysEx message received at the BCR's MIDI IN and passed on to the computer via USB can maximally be 1019 bytes long: longer messages arrive incorrectly at the computer.
What happens exactly depends on the precise length of the message and on what has been sent before:
- A message can get mutilated: i.e. some bytes are swallowed.
- A message can get buffered, i.e. is not output immediately, but only after some trigger (an EOX (F7h) byte at a suitable location?): the computer program then suddenly receives a long "group message". (I haven't checked the upper limit of this, but I've seen a "group message" of 46882 bytes!)
This limit of 1019 bytes might seem reasonble, but there ARE devices that use longer messages.
For instance, Behringer's own FCB1010 MIDI Foot Controller outputs its Global Setup as a single SysEx message of 2352 bytes.
So you can't use the BCF or BCR to retrieve the FCB1010's Global Setup!
Input messages in Operating Mode U-2:
In this case the messages received at the BCR's MIDI IN are sent to both the computer and MIDI OUT B/THRU.
You'd think that anything received at MIDI IN could simply be passed on to MIDI OUT B/THRU (isn't that what THRU is supposed to mean?), but alas: the limitation of 1019 bytes applies to MIDI OUT B/THRU as well!
This seems to indicate that the limit of 1019 bytes is caused by the BCR itself, not by the USB driver on the computer.
Output messages:
SysEx messages sent FROM the computer TO the BCF/BCR via USB and from there to
MIDI OUT A or B/THRU (Operating Mode U-2/3/4) have a maximum length of 8078 bytes.
Beyond that, similar problems arise as in the "inward" direction, i.e. mutilation and buffering.
By contrast, my two Roland USB-to-MIDI devices (a GS-10 (a guitar effect unit, several years older than the BCF/BCR) and an Octa-Capture (a modern USB audio interface)) seem to work fine with SysEx messages of at least 65536 bytes in both directions.
So Behringer haven't exactly "done their homework"...
Mark.