Compatible MIDI interfaces

BNi

I am currently using an external MIDI merger and a Kenton thru-5 to add more I/O to the rk006.
However, I would like to use a 4x4 midi interface for that purpose. It just seems more elegant and would reduce cabling drastically. So far, USB host mode has been working great throughout, but I'm having problems when using midi interfaces. So far I have tried

Midiman midisport 4x4 anniversary edition. USB 2.0 and works on Linux and Mac without drivers, which tells me it should be class compliant.
The USB indicator is pulsing as it should, but no midi is passed to or from the device.
ESI M4U miditerminal 4x4 USB 2.0 class compliant device.
MIDI is only passed to outputs 1 and 2. CC messages are not passed on to the outputs. All 4 MIDI inputs seem to work.

Have any of you gathered experience which MIDI interfaces are functioning with the rk006?

albert

Unfortunately we don't have those interfaces over here to test with. Maybe you can provide a so called 'USB device descriptor dump'. On Windows you can do that with this tool : https://www.thesycon.de/eng/usb_descriptordumper.shtml , on Linux it's a simple 'lsusb -v' , on MacOSX it's cumbersome (of course: because it's Apple... everything has to be 'different' and complicated)

The midiman products have a non-standard USB MIDI implementation, for which Linux has it's own specialized drivers.

The ESI M4U most probably has 4 separate MIDI busses : the RK006 supports up to 2 midi-out busses per device, so the behaviour you're observing would be as intended.
note: the RK006 itself also exposes a lot of MIDI busses to the USB host (up to 11x for the outputs), the first bus acts as a 'catch/send ALL'

BNi

ok, so the USB dumps are here

ESI Miditerminal M4U

Bus 002 Device 003: ID 0a92:1020 EGO SYStems, Inc. M4U
Couldn't open device, some information will be missing
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10
bDeviceClass 0
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 8
idVendor 0x0a92 EGO SYStems, Inc.
idProduct 0x1020 M4U
bcdDevice 1.02
iManufacturer 1 Ego Systems Inc
iProduct 2 ESI-M4U
iSerial 3 ct021002AD
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x00c5
bNumInterfaces 2
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 100mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 1 Control Device
bInterfaceProtocol 0
iInterface 0
AudioControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 1 (HEADER)
bcdADC 1.00
wTotalLength 0x0009
bInCollection 1
baInterfaceNr(0) 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 1 Audio
bInterfaceSubClass 3 MIDI Streaming
bInterfaceProtocol 0
iInterface 0
MIDIStreaming Interface Descriptor:
bLength 7
bDescriptorType 36
bDescriptorSubtype 1 (HEADER)
bcdADC 1.00
wTotalLength 0xa100
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 1 Embedded
bJackID 1
iJack 0
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 1 Embedded
bJackID 5
iJack 0
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 1 Embedded
bJackID 9
iJack 0
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 1 Embedded
bJackID 13
iJack 0
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 2 External
bJackID 2
iJack 0
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 2 External
bJackID 6
iJack 0
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 2 External
bJackID 10
iJack 0
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 2 External
bJackID 14
iJack 0
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 1 Embedded
bJackID 3
bNrInputPins 1
baSourceID( 0) 2
BaSourcePin( 0) 1
iJack 0
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 1 Embedded
bJackID 7
bNrInputPins 1
baSourceID( 0) 6
BaSourcePin( 0) 1
iJack 0
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 1 Embedded
bJackID 11
bNrInputPins 1
baSourceID( 0) 10
BaSourcePin( 0) 1
iJack 0
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 1 Embedded
bJackID 15
bNrInputPins 1
baSourceID( 0) 14
BaSourcePin( 0) 1
iJack 0
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 2 External
bJackID 4
bNrInputPins 1
baSourceID( 0) 1
BaSourcePin( 0) 1
iJack 0
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 2 External
bJackID 8
bNrInputPins 1
baSourceID( 0) 5
BaSourcePin( 0) 1
iJack 0
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 2 External
bJackID 12
bNrInputPins 1
baSourceID( 0) 9
BaSourcePin( 0) 1
iJack 0
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 2 External
bJackID 16
bNrInputPins 1
baSourceID( 0) 13
BaSourcePin( 0) 1
iJack 0
Endpoint Descriptor:
bLength 9
bDescriptorType 5
bEndpointAddress 0x01 EP 1 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0020 1x 32 bytes
bInterval 0
bRefresh 0
bSynchAddress 0
MIDIStreaming Endpoint Descriptor:
bLength 8
bDescriptorType 37
bDescriptorSubtype 1 (GENERAL)
bNumEmbMIDIJack 4
baAssocJackID( 0) 1
baAssocJackID( 1) 5
baAssocJackID( 2) 9
baAssocJackID( 3) 13
Endpoint Descriptor:
bLength 9
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0020 1x 32 bytes
bInterval 0
bRefresh 0
bSynchAddress 0
MIDIStreaming Endpoint Descriptor:
bLength 8
bDescriptorType 37
bDescriptorSubtype 1 (GENERAL)
bNumEmbMIDIJack 4
baAssocJackID( 0) 3
baAssocJackID( 1) 7
baAssocJackID( 2) 11
baAssocJackID( 3) 15
!<

M-Audio Midisport 4x4 anniversary edition

Bus 002 Device 005: ID 0763:1060 M-Audio MIDISPORT 4x4 Anniv
Couldn't open device, some information will be missing
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10
bDeviceClass 0
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x0763 M-Audio
idProduct 0x1060
bcdDevice 1.04
iManufacturer 1 M-Audio
iProduct 2 MIDISPORT 4x4 Anniv
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x00c1
bNumInterfaces 2
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 400mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 1 Control Device
bInterfaceProtocol 0
iInterface 2
AudioControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 1 (HEADER)
bcdADC 1.00
wTotalLength 0x0009
bInCollection 1
baInterfaceNr(0) 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 1 Audio
bInterfaceSubClass 3 MIDI Streaming
bInterfaceProtocol 0
iInterface 2
MIDIStreaming Interface Descriptor:
bLength 7
bDescriptorType 36
bDescriptorSubtype 1 (HEADER)
bcdADC 1.00
wTotalLength 0x009d
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 1 Embedded
bJackID 3
bNrInputPins 1
baSourceID( 0) 2
BaSourcePin( 0) 1
iJack 3
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 2 External
bJackID 2
iJack 3
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 1 Embedded
bJackID 7
bNrInputPins 1
baSourceID( 0) 6
BaSourcePin( 0) 1
iJack 4
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 2 External
bJackID 6
iJack 4
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 1 Embedded
bJackID 10
bNrInputPins 1
baSourceID( 0) 9
BaSourcePin( 0) 1
iJack 7
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 2 External
bJackID 9
iJack 7
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 1 Embedded
bJackID 12
bNrInputPins 1
baSourceID( 0) 11
BaSourcePin( 0) 1
iJack 8
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 2 External
bJackID 11
iJack 8
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 1 Embedded
bJackID 1
iJack 5
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 2 External
bJackID 4
bNrInputPins 1
baSourceID( 0) 1
BaSourcePin( 0) 1
iJack 5
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 1 Embedded
bJackID 5
iJack 6
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 2 External
bJackID 8
bNrInputPins 1
baSourceID( 0) 5
BaSourcePin( 0) 1
iJack 6
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 1 Embedded
bJackID 13
iJack 7
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 2 External
bJackID 14
bNrInputPins 1
baSourceID( 0) 13
BaSourcePin( 0) 1
iJack 7
MIDIStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 2 (MIDI_IN_JACK)
bJackType 1 Embedded
bJackID 15
iJack 8
MIDIStreaming Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (MIDI_OUT_JACK)
bJackType 2 External
bJackID 16
bNrInputPins 1
baSourceID( 0) 15
BaSourcePin( 0) 1
iJack 8
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x04 EP 4 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
MIDIStreaming Endpoint Descriptor:
bLength 8
bDescriptorType 37
bDescriptorSubtype 1 (GENERAL)
bNumEmbMIDIJack 4
baAssocJackID( 0) 1
baAssocJackID( 1) 5
baAssocJackID( 2) 13
baAssocJackID( 3) 15
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x86 EP 6 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
MIDIStreaming Endpoint Descriptor:
bLength 8
bDescriptorType 37
bDescriptorSubtype 1 (GENERAL)
bNumEmbMIDIJack 4
baAssocJackID( 0) 3
baAssocJackID( 1) 7
baAssocJackID( 2) 10
baAssocJackID( 3) 12
!<

So do i understand correctly, chances of getting 4x4 MIDI interfaces to work are slim because of the 2 out busses per USB device limit? For my purposes, the outputs can simply be 4 thrus from the "out from rk006" bus and don't need to be adressed seperately.

Also, is there a limit how many USB devices rk006 can use simultaneously?

grit

In order to keep things tight we limited the RK006 to 4 devices on a hub since hubs which have more ports usually are 'hubs within hubs'. Normally 4 ports is the max a usb hub-chip can handle.

This might seem overcautious, but in a single USB port you can have more than one midi bus (as you have noticed). We have added support up to 2 buses per devices since that makes life easier in hosting some Korg devices) and still keeps MIDI data manageable if you have 4 usb devices with each 2 buses connected to the RK006.
The RK006 itself enumerates 14 buses (a bus can each transfer 16 midi channels) separately if you connect it to a PC.
But: If you want to host it on a 'lesser type usb host' (meaning: the general 1 port, 1 bus type host) we have a special 1-all-in 1-all-out mode so you can at least access all ports in a system like that without having tedious routing done. If the midiman would have a mode like that it would be no problem. A secondary RK006 on a RK006 does work like that (but I would advise routing that through with just a single TRS cable by the way)