This API [NPA_CDM_Passthru] provides applications the ability to communicate directly with a device. This provides a vendor with a communications channel to allow for vendor-specific commands and data to be sent to and from the device. For example, vendor-specific device diagnostic information could be sent to an application using this API. CDMs must register for the specific functions that it will process. See the NPA_CDM_Passthru API in Functions for more details.