I'm currently working on a graduation project. However I have never worked with USB before. I'm using the Example provided by Keil to initiate a VCOM drive.
However I now want to use 2 VCOM drives via 1 USB connection. It's going to be used to communicate with the PC.
While one of these VCOM ports will be used to convert serial data from the RS232 connection to USB. While the other is being used to communicate with the pc.
While I have no troubles with the Keil example, I was having trouble to initiate a second VCOM. I have found a similar subject on this discussion forum ( http://www.keil.com/forum/15274/ ) I figured it would provide what I needed except that it was defined to support up to five drives.
I configured it exactly as was stated in this post by Tsuneo Chinzei. I have changed the .INF file as was described by Tsuneo Chinzei, however I have only included two extra USB\VID's instead of the proposed 5
[DeviceList] %DESCRIPTION%=MCB2300USB, USB\VID_c251&PID_1705, USB\VID_FF00&PID_0300&MI_00, USB\VID_FF00&PID_0300&MI_02
However by connecting it to the PC it just says that the device is unknown. By changing the DeviceClass in USB_DeviceDescriptor from USB_DEVICE_CLASS_MISCELLANEOUS to USB_DEVICE_CLASS_COMMUNICATIONS
However, while it recognizes the *.INF file, the computer crashes as soon as I want to install the drivers.