I wish to develop an application which implements two-way communication with a barcode reader where the application sends back an accept/reject signal to the barcode reader to indicate success or failure and the barcode reader interprets with a different beep, red bulb or whatever (depending on the brand). For this reason using the Keyboard Wedge or one-way communication does not suit this scenario (this use case will have people away from the computer with wireless handheld barcode scanners, so they won't be seeing anything on screen).
I think that for this scenario I have to use HID POS, but I am bit stuck from where I should start, (i.e. what API calls or signals should I send?).
Also do I have to look for some specific support for this in the barcode scanners or is HID POS with 2-way accept/reject model supported by all USB devices?