[wdmaudiodev] Re: MIDI SYSEX response lost

  • From: Timothy Knudtson <tknudtson@xxxxxxxxxxxxxxxxx>
  • To: wdmaudiodev@xxxxxxxxxxxxx
  • Date: Fri, 23 Aug 2013 12:17:44 -0600

I have tried other controllers and don't see this effect. We have 5 products 
and 3 of the 5 are effected in this way.

Timothy Knudtson

On Aug 23, 2013, at 12:10 PM, Matthew van Eerde 
<Matthew.van.Eerde@xxxxxxxxxxxxx> wrote:

> Does using a different USB controller have any effect?
> From: wdmaudiodev-bounce@xxxxxxxxxxxxx 
> [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Timothy Knudtson
> Sent: Friday, August 23, 2013 11:00 AM
> To: wdmaudiodev@xxxxxxxxxxxxx
> Subject: [wdmaudiodev] MIDI SYSEX response lost
> Our company is working on MIDI devices that are configured using SYSEX 
> messages. I am seeing a weird behavior with Windows 7 and Windows 8. I send 
> 5-10 SYSEX messages to the device and receive the expected responses, then 
> for the next 20-300 messages the responses do not come back. After sending 
> those 20-300 SYSEX messages the response start coming in. I have placed a 
> Beagle (USB logger) on the line and setup USB logging in windows. From what I 
> see the responses are being sent from the device. The response size of the 
> SYSEX messages is less than 128 bytes (around 50 bytes on average). I have 
> tried using the WindowsMM libraries and the KS libraries and they both 
> exhibit the same behavior. My felling is that the issue lies in the 
> USBAudio.sys driver.
> This device works on Windows XP, Mac, and iOS. I have not tested on any other 
> platform.
> Any help would be appreciated. Thank you.
> Timothy Knudtson
> iConnectivity

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