Request a Unique Product ID (PID)
Each USB device attached to a USB host must have a unique Vendor ID (VID), Product ID (PID) and Serial String combination in order to function properly.
Product ID (PID)
Product IDs are assigned and maintained by the vendor who owns the VID. Product IDs are normally used to distinguish between different products under a single VID — this is at the discretion of the vendor. If a Silicon Labs USB device is used in a product, it is permissible for a company to use their own VID or a Silicon Labs VID. To use a Silicon Labs VID, you must be issued a custom PID directly from Silicon Labs. It is not allowed to use a random PID under the Silicon Labs VID, nor to use a PID assigned to a different company.
The Serial String is used to distinguish between multiple devices which have the same VID and PID. It is the responsibility of the product manufacturer to serialize their own USB devices, but it is possible for Silicon Labs to pre-program the VID and PID into CP210x USB devices and perform serialization.
For detailed instructions on how to custom program CP210x devices into your system, refer to the following resources:
Custom Pre-Programming Requests
To request that Silicon Labs pre-program a custom VID/PID number and/or serialize devices prior to shipment of CP21xx USB devices, contact your local Silicon Labs sales office or authorized representative.