1. I have a USB bulk device, and have developed the framework for the same.My User App communicates with the framework which in turn talks to the device and returns back data to the user app. The complete flow works fine with the single application,
Below are the Tasks done at the framework level:
.a) At the constructor stage , i enumerate the device and store the IOUSBDeviceInterface and IOUSBInterfaceInterface in a structure of my bulk device attached.
Developed an API that
b. Opens the device using ,
status = (*device->deviceInterface)->USBDeviceOpen(device->deviceInterface);
// device is the structure in which i am storing the data
c. Open the interface
status = (*device->InterfaceInterface)->USBDeviceOpen(device->InterfaceInterface);
d. Write the data
status = (*device->InterfaceInterface)->WritePipe(device->InterfaceInterface, 1, &pCommand->SeqNum, pCommand->CmdSize);
e. Read the data
status = (*device->InterfaceInterface)->ReadPipe(device->InterfaceInterface, 2 ,&pRsp->SeqNum,&size);
f. Close the Interface
g. Close the device. /////
In a case, when I take more than one application, that communicates with the USB device, I do folowing
a. run App1
b. run App2
Both Application loads the same framework in order to talk to the device.
Now when I run the first application, it loads the framework (and will keep it loaded til lthe app exits) And Also I run the second application,
At this point both of the applications are running. Now when I try to access the application that was first run, The application failes to OPEN THE INTERFACE with following error c20 i.e NO SUCH DEVICE
And , then when now i try to access the application run later, it fails to OPEN THE DEVICE. i.e c25, i.e EXCUSIVE ACCESS.
What can be the possible issue ? All suggestions / comments are welcome
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