Question

I have a HID device (picoLCD monochrome display), that I open in a Windows program written in C#. I get 3 HID "instances" of my device with the following paths:

_devicePath = "\\\\?\\hid#vid_04d8&pid_c002&col01#7&12adec39&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}"
_devicePath = "\\\\?\\hid#vid_04d8&pid_c002&col02#7&12adec39&0&0001#{4d1e55b2-f16f-11cf-88cb-001111000030}"
_devicePath = "\\\\?\\hid#vid_04d8&pid_c002&col03#7&12adec39&0&0002#{4d1e55b2-f16f-11cf-88cb-001111000030}"

They all have the same VID and PID, but different "col". What does this parameter mean? And why there are 3 device "descriptors" for one device?

UsbView shows only one physical device with 2 endpoints:

Device Descriptor:
bcdUSB:             0x0200
bDeviceClass:         0x00
bDeviceSubClass:      0x00
bDeviceProtocol:      0x00
bMaxPacketSize0:      0x08 (8)
idVendor:           0x04D8 (Microchip Technology Inc.)
idProduct:          0xC002
bcdDevice:          0x0002
iManufacturer:        0x01
iProduct:             0x02
iSerialNumber:        0x03
bNumConfigurations:   0x01

ConnectionStatus: DeviceConnected
Current Config Value: 0x01
Device Bus Speed:     Full
Device Address:       0x05
Open Pipes:              2

Endpoint Descriptor:
bEndpointAddress:     0x81  IN
Transfer Type:   Interrupt
wMaxPacketSize:     0x0040 (64)
bInterval:            0x01

Endpoint Descriptor:
bEndpointAddress:     0x01  OUT
Transfer Type:   Interrupt
wMaxPacketSize:     0x0040 (64)
bInterval:            0x01
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Solution

Looks like it some sort of collection id (for example HIDClass Hardware IDs for Top-Level Collections)

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